I don't think there is any deep reason to separate CUs and TUs in
dwarf2_per_bfd.  This patch removes all_type_units and unifies these
two containers.  Some minor tweaks are needed to the index writers,
because both forms of index keep CUs and TUs separate;

Regression tested on x86-63 Fedora 32.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.h (struct tu_stats) <nr_tus>: New member.
	(struct dwarf2_per_bfd) <get_cutu, get_tu>: Remove
	<get_cu>: Now inline.
	<all_type_units>: Remove.
	* dwarf2/read.c (dwarf2_per_bfd::~dwarf2_per_bfd): Update.
	(dwarf2_per_bfd::get_cutu, dwarf2_per_bfd::get_cu)
	(dwarf2_per_bfd::get_tu): Remove.
	(dwarf2_per_bfd::allocate_signatured_type): Update nr_tus.
	(create_signatured_type_table_from_index)
	(create_signatured_type_table_from_debug_names)
	(dw2_symtab_iter_next, dwarf2_base_index_functions::print_stats)
	(dwarf2_base_index_functions::expand_all_symtabs)
	(dw2_expand_marked_cus, dw_expand_symtabs_matching_file_matcher)
	(dwarf2_base_index_functions::map_symbol_filenames)
	(dw2_debug_names_iterator::next, dwarf2_initialize_objfile)
	(add_signatured_type_cu_to_table, create_all_type_units)
	(add_type_unit, build_type_psymtabs_1, print_tu_stats)
	(create_all_comp_units): Update.
	* dwarf2/index-write.c (check_dwarf64_offsets, write_gdbindex)
	(write_debug_names): Update.

In a patch series I am working on, I'd like to have a non-POD member
in dwarf2_per_cu_data.  This currently can't be done because
dwarf2_per_cu_data is allocated on an obstack and initialized with
memset.

This patch changes the DWARF reader to allocate objects of this type
with 'new'.  The various "subclasses" of this type (signatured_type in
particular) are now changed to derive from dwarf2_per_cu_data, and
also use 'new' for allocation.

Regression tested on x86-64 Fedora 32.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.h (struct dwarf2_per_bfd) <allocate_per_cu,
	allocate_signatured_type>: Change return type.
	<all_comp_units, all_type_units>: Hold unique pointers.
	(struct dwarf2_per_cu_data): Add constructor and initializers.
	(struct signatured_type): Derive from dwarf2_per_cu_data.
	* dwarf2/read.c (type_unit_group): Derive from
	dwarf2_per_cu_data.
	(dwarf2_per_bfd::get_cutu, dwarf2_per_bfd::get_cu)
	(dwarf2_per_bfd::get_tu)
	(dwarf2_per_bfd::allocate_signatured_type)
	(dwarf2_per_bfd::allocate_signatured_type)
	(create_cu_from_index_list, create_cus_from_index_list)
	(create_signatured_type_table_from_index)
	(create_signatured_type_table_from_debug_names)
	(create_addrmap_from_aranges)
	(dwarf2_base_index_functions::find_last_source_symtab)
	(dw_expand_symtabs_matching_file_matcher)
	(dwarf2_gdb_index::expand_symtabs_matching)
	(dwarf2_base_index_functions::map_symbol_filenames)
	(create_cus_from_debug_names_list)
	(dw2_debug_names_iterator::next)
	(dwarf2_debug_names_index::expand_symtabs_matching)
	(create_debug_type_hash_table, add_type_unit)
	(fill_in_sig_entry_from_dwo_entry, lookup_dwo_signatured_type):
	Update.
	(allocate_type_unit_groups_table): Use delete.
	(create_type_unit_group): Change return type.  Use new.
	(get_type_unit_group, build_type_psymtabs_1)
	(build_type_psymtab_dependencies)
	(process_skeletonless_type_unit, set_partial_user)
	(dwarf2_build_psymtabs_hard, read_comp_units_from_section)
	(create_cus_hash_table, queue_and_load_dwo_tu, follow_die_sig_1)
	(read_signatured_type): Update.
	(dwarf2_find_containing_comp_unit): Change type of
	'all_comp_units'.
	(run_test): Update.
	(dwarf2_per_bfd::allocate_per_cu)
	(dwarf2_per_bfd::allocate_signatured_type): Change return type.
	Use new.
	(add_signatured_type_cu_to_table): Update.
	* dwarf2/index-write.c (write_one_signatured_type)
	(check_dwarf64_offsets, psyms_seen_size, write_gdbindex)
	(write_debug_names): Update.

The only callers of get_image_name are nat/windows-nat.c, so make it
static.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* nat/windows-nat.h (get_image_name): Don't declare.
	* nat/windows-nat.c (get_image_name): Now static.

This moves the new DLL-loading code into nat/windows-nat.c, and
changes both gdb and gdbserver to use the shared code.  One
client-provided callback, handle_load_dll, is changed to allow the
code to be shared.  This callback was actually never called from
nat/windows-nat.c; maybe I had planned to share more here and then
didn't finish... I'm not sure.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c (windows_nat::handle_load_dll): Update.
	(windows_nat_target::get_windows_debug_event): Call
	dll_loaded_event.
	(windows_add_all_dlls, windows_add_dll): Move to
	nat/windows-nat.c.
	* nat/windows-nat.h (handle_load_dll): Change parameters.
	(dll_loaded_event, windows_add_all_dlls): Declare.
	* nat/windows-nat.c (windows_add_dll, windows_add_all_dlls): Move
	from windows-nat.c.
	(dll_loaded_event): New function.

gdbserver/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* win32-low.cc (do_initial_child_stuff): Update.
	(windows_nat::handle_load_dll): Rename from win32_add_one_solib.
	Change parameter type.
	(win32_add_dll, win32_add_all_dlls)
	(windows_nat::handle_load_dll): Remove.
	(get_child_debug_event): Call dll_loaded_event.

This changes gdbserver to use the function indirection code that was
just moved into nat/windows-nat.[ch].  One additional function is used
by gdbserver that was not used by gdb.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* nat/windows-nat.h (GenerateConsoleCtrlEvent): New define.
	(GenerateConsoleCtrlEvent_ftype, GenerateConsoleCtrlEvent):
	Declare.
	* nat/windows-nat.c (GenerateConsoleCtrlEvent): Define.
	(initialize_loadable): Initialize GenerateConsoleCtrlEvent.

gdbserver/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* win32-low.cc (GETPROCADDRESS): Remove.
	(winapi_DebugActiveProcessStop, winapi_DebugSetProcessKillOnExit)
	(winapi_DebugBreakProcess, winapi_GenerateConsoleCtrlEvent)
	(winapi_Wow64SetThreadContext, win32_Wow64GetThreadContext)
	(win32_Wow64SetThreadContext): Remove.
	(win32_set_thread_context, do_initial_child_stuff)
	(win32_process_target::attach, win32_process_target::detach):
	Update.
	(winapi_EnumProcessModules, winapi_EnumProcessModulesEx)
	(winapi_GetModuleInformation, winapi_GetModuleInformationA):
	Remove.
	(win32_EnumProcessModules, win32_EnumProcessModulesEx)
	(win32_GetModuleInformation, win32_GetModuleInformationA):
	Remove.
	(load_psapi): Remove.
	(win32_add_dll, win32_process_target::request_interrupt): Update.
	(initialize_low): Call initialize_loadable.

gdb and gdbserver both look for functions in some Windows DLLs at
runtime.  This patch moves this code out of gdb and into
nat/windows-nat, so it can be shared by both programs.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c: Move code to nat/windows-nat.[ch].
	(_initialize_windows_nat): Call initialize_loadable.
	* nat/windows-nat.h (AdjustTokenPrivileges)
	(DebugActiveProcessStop, DebugBreakProcess)
	(DebugSetProcessKillOnExit, EnumProcessModules)
	(EnumProcessModulesEx, GetModuleInformation)
	(GetModuleFileNameExA, GetModuleFileNameExW)
	(LookupPrivilegeValueA, OpenProcessToken, GetConsoleFontSize)
	(GetCurrentConsoleFont, Wow64SuspendThread)
	(Wow64GetThreadContext, Wow64SetThreadContext)
	(Wow64GetThreadSelectorEntry): Move from windows-nat.c.
	(AdjustTokenPrivileges_ftype)
	(DebugActiveProcessStop_ftype, DebugBreakProcess_ftype)
	(DebugSetProcessKillOnExit_ftype, EnumProcessModules_ftype)
	(EnumProcessModulesEx_ftype, GetModuleInformation_ftype)
	(GetModuleFileNameExA_ftype, GetModuleFileNameExW_ftype)
	(LookupPrivilegeValueA_ftype, OpenProcessToken_ftype)
	(GetConsoleFontSize_ftype)
	(GetCurrentConsoleFont_ftype, Wow64SuspendThread_ftype)
	(Wow64GetThreadContext_ftype, Wow64SetThreadContext_ftype)
	(Wow64GetThreadSelectorEntry_ftype): Likewise.
	(initialize_loadable): Declare.
	* nat/windows-nat.c (AdjustTokenPrivileges)
	(DebugActiveProcessStop, DebugBreakProcess)
	(DebugSetProcessKillOnExit, EnumProcessModules)
	(EnumProcessModulesEx, GetModuleInformation, GetModuleFileNameExA)
	(GetModuleFileNameExW, LookupPrivilegeValueA, OpenProcessToken)
	(GetCurrentConsoleFont, GetConsoleFontSize, Wow64SuspendThread)
	(Wow64GetThreadContext, Wow64SetThreadContext)
	(Wow64GetThreadSelectorEntry): Define.
	(bad, bad_GetCurrentConsoleFont, bad_GetConsoleFontSize): Move
	from windows-nat.c.
	(initialize_loadable): Likewise, and rename.

windows-nat.c defines a number of replacement functions that simply
return zero.  This patch removes these in favor of a couple of
template functions.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c (bad_GetModuleFileNameEx): Remove define.
	(bad_DebugActiveProcessStop, bad_DebugBreakProcess)
	(bad_DebugSetProcessKillOnExit, bad_EnumProcessModules)
	(bad_GetModuleFileNameExW, bad_GetModuleFileNameExA)
	(bad_GetModuleInformation, bad_OpenProcessToken): Remove.
	(bad): New template functions.
	(_initialize_loadable): Update.

Tankut's recent patches made me realize that thread_pool::post_task
should have used an rvalue reference for its parameter.  This patch
makes this change.

gdbsupport/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* thread-pool.cc (thread_pool::post_task): Update.
	* thread-pool.h (class thread_pool) <post_task>: Take rvalue
	reference to function.

Running the AdaCore internal test suite with -fgnat-encodings=minimal
found a gdb crash.  The bug is that GDB ends up with a typedef in
ada_index_type, resulting in a NULL dereference.

This crash can be reproduced using GCC 11 with the included test case.

Tested on x86-64 Fedora 32.  Because this is Ada-specific, and was
already reviewed by Joel, I am going to check it in.

2021-04-30  Tom Tromey  <tromey@adacore.com>

	* ada-lang.c (ada_index_type): Use ada_check_typedef.

gdb/testsuite/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* gdb.ada/enum_idx_packed/pck.ads (My_Enum, My_Array_Type)
	(Confused_Array): New types.
	* gdb.ada/enum_idx_packed/foo.adb (Confused_Array): New variable.
	* gdb.ada/enum_idx_packed.exp: Add new tests.

	PR 27801
	* mach-o.c (bfd_mach_o_core_fetch_environment): Use bfd_get_32 to
	read 32-bit value.

	PR 27799
	* elf32-xtensa.c (elf_xtensa_grok_prstatus): Check for core notes
	that are too small.

	PR 27797
	* libbfd.c (bfd_realloc_or_free): Do not free a pointer than has
	been realloc'ed to size 0.

	PR 27796
	* dwarf.c (load_debug_sup_file): Allocate memory for filename in
	.debug_sup section.

	PR 27795
	* coff-rs6000.c (_bfd_xcoff_read_ar_hdr): Check for invalid name
	lengths.

Once in a while, I run into this timeout:
...
FAIL: gdb.mi/mi-sym-info.exp: List all variables from debug information \
  only (timeout)
...

I can make the timeout reproducible by setting timeout to 8s (instead of the
default 10s) for the duration of that test.

Make the test-case more stable by fixing all timeouts caused by setting
timeout to 5, either by adding with_timeout_factor, or increasing its factor.

Tested on x86_64-linux.  Also tested in parallel with stress -c 5, to simulate
a busy system in another way.

gdb/testsuite/ChangeLog:

2021-04-30  Tom de Vries  <tdevries@suse.de>

	* gdb.mi/mi-sym-info.exp: Add with_timeout_factor, and increase
	existing timeout factors.

Since commit 2d61316c "[gdb/testsuite] Fix buffer full errors in
gdb.mi/mi-sym-info.exp", we have a duplicate test name:
...
Running src/gdb/testsuite/gdb.mi/mi-sym-info.exp ...
DUPLICATE: gdb.mi/mi-sym-info.exp: List all variables
...

This is caused by a copy-paste accident: the idea was to copy the test, edit
it, and then remove the old test, but I forgot to remove the old one.
Remove it now.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2021-04-30  Tom de Vries  <tdevries@suse.de>

	* gdb.mi/mi-sym-info.exp: Remove duplicate test.

Since commit 6d5702a5 "Fix test case gdb.base/valgrind-bt.exp" I run into:
...
FAIL: gdb.base/valgrind-infcall-2.exp: target remote for vgdb (timeout)
FAIL: gdb.base/valgrind-infcall-2.exp: monitor v.set gdb_output (timeout)
...

The commit adds this line in proc vgdb_start:
...
    set vgdbcmd "set remotetimeout 3"
...
which has no effect given that the value of var vgdbcmd is not used before
it's overwritten.  We can fix this by doing instead:
...
    set_remotetimeout 3
...

The FAIL I'm observing is fixed by increasing the remotetimeout value to 4.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2021-04-29  Tom de Vries  <tdevries@suse.de>

	PR testsuite/27786
	* lib/valgrind.exp (vgdb_start): Use set_remotetimeout.  Increase
	remotetimeout to 4.

In a review, I suggested to use "namespace gdb::observers" instead of
two separate namespace declarations.  I didn't realize that this was a
C++17 feature, which breaks compilers that default to an earlier version
of the language, like g++ 4.8.  Change it back to two separate
declarations.

gdb/ChangeLog:

	* auto-load.h: Split namespace declaration.

Change-Id: I701537161967fbd9fcc298ff600bd072aab1251d

	PR 27793
	* som.c (som_slurp_symbol_table): Assign symbols without any scope
	to the undefined section.
	(som_decode_symclass): Check for a missing symbol section.
	* syms.c (bfd_decode_symclass): Likewise.

	PR 27792
	* som.c (som_slurp_string_table): Place a terminating NUL byte at
	the end of the table.
	(som_slurp_symbol_table): Check for an over-large offset into the
	string string table.

These two variables:

      struct regcache *regcache = get_thread_regcache (tp);
      const address_space *aspace = regcache->aspace ();

are only needed inside the "if".  Getting a thread's regcache is a
somewhat expensive operation, so it's good to avoid it if not necessary.
Move the variable declarations and their initialization to the "if"
scope.

gdb/ChangeLog:

	* infrun.c (save_waitstatus): Move variables to inner scope.

Change-Id: Ief1463728755b4dcc142c0a0a76896e9d594ae84

Five of them fail for Cygwin and MingW. Adjust four and move one to the
ELF-only section.

 PR 27594
 * doc/binutils.texi (windres): Correct the description of the
 default value of the --preprocessor argument.

Allow a few more expression forms when the entire expression can be
resolved at assembly time. For this, i386_validate_fix() needs to
arrange for all processing of the relocation to be deferred to
tc_gen_reloc().

So far this (counter-intuitively) produced the size as recorded in the
(section) symbol. Obtain the section's size instead for section symbols.
(I wonder whether STT_SECTION symbols couldn't properly hold the
section's size in their st_size field, which in turn would likely mean
the internal symbol would also have its size properly updated.)

Note that this is not the same as the .sizeof.() pseudo-operator: @size
yields the local file's contribution to a section, while .sizeof.() gets
resolved by the linker to produce the final full section's size.

As to the 3rd each of the expected output lines in the changed testcase:
I can't find justification for zzz to come after yyy despite them being
defined in the opposite order in source. Therefore I think it's better
to permit both possible outcomes.

Some errors introduced in commit:

  commit edeaceda
  Date:   Thu Aug 27 16:53:13 2020 +0100

      gdb: startup commands to control Python extension language

gdb/ChangeLog:

	* NEWS: Fix typo and stray full stop.

Currently, the Ada expression parser treats 'null' as an integer 0.
However, this causes overloading to fail in certain cases.

This patch changes the Ada expression parser to use a special type for
'null'.  I chose pointer-to-int0, because I think that's not likely to
be needed for any other Ada expression.  Note this works because a
"mod 1" type has an underlying non-zero byte size; the test includes a
check for this.

The output is changed so that "print null", by default, shows "null".
And, ada_type_match is changed both to recognize the special null type
and to remove a bit of weird code related to how pointers are treated
for overload type matching.

Tested on x86-64 Fedora 32.  Because this only touches Ada, and Joel
already approved it internally at AdaCore, I am checking it in.

gdb/ChangeLog
2021-04-28  Tom Tromey  <tromey@adacore.com>

	* ada-exp.y (primary): Use new type for null pointer.
	* ada-lang.c (ada_type_match): Remove "may_deref"
	parameter.  Handle null pointer.
	(ada_args_match): Update.
	* ada-valprint.c (ada_value_print_ptr, ada_value_print):
	Handle null pointer.

gdb/testsuite/ChangeLog
2021-04-28  Tom Tromey  <tromey@adacore.com>

	* gdb.ada/null_overload.exp: New file.
	* gdb.ada/null_overload/foo.adb: New file.

Clean up a few places where we are not using @env{...} to reference
environment variables.

gdb/doc/ChangeLog:

	* gdb.texinfo (Initialization Files): Use @env when referencing
	environment variables.
	(Shell Commands): Likewise.
	(Starting): Likewise.
	(Arguments): Likewise.
	(Environment): Likewise.
	(Edit): Likewise.
	(Compiling and Injecting Code): Likewise.
	(Files): Likewise.
	(Command History): Likewise.
	(Screen Size): Likewise.
	(Emacs): Likewise.

bfd	* elf.c (_bfd_elf_maybe_function_sym): Do not accept annobin
	symbols as potential function symbols.
	* elfnn-aarch64.c (elfNN_aarch64_maybe_function_sym): Likewise.
	* elf64-ppc.c (ppc64_elf_maybe_function_sym): Likewise.
	* elf32-arm.c (elf32_arm_maybe_function_sym): Likewise.

ld	* testsuite/ld-elf/anno-sym.s: New test source file.
	* testsuite/ld-elf/anno-sym.d: New test driver.
	* testsuite/ld-elf/anno-sym.l: New test error output.

Add two new commands to GDB that can be placed into the early
initialization to control how Python starts up.  The new options are:

  set python ignore-environment on|off
  set python dont-write-bytecode auto|on|off

  show python ignore-environment
  show python dont-write-bytecode

These can be used from GDB's startup file to control how the Python
extension language behaves.  These options are equivalent to the -E
and -B flags to python respectively, their descriptions from the
Python man page:

  -E     Ignore environment variables like PYTHONPATH and PYTHONHOME
         that modify the  behavior  of  the  interpreter.

  -B     Don't write .pyc files on import.

gdb/ChangeLog:

	* NEWS: Mention new commands.
	* python/python.c (python_ignore_environment): New static global.
	(show_python_ignore_environment): New function.
	(set_python_ignore_environment): New function.
	(python_dont_write_bytecode): New static global.
	(show_python_dont_write_bytecode): New function.
	(set_python_dont_write_bytecode): New function.
	(_initialize_python): Register new commands.

gdb/doc/ChangeLog:

	* python.texinfo (Python Commands): Mention new commands.

gdb/testsuite/ChangeLog:

	* gdb.python/py-startup-opt.exp: New file.

Now that both Python and Guile are fully initialized from their
respective finish_initialization methods, the "finish" in the method
name doesn't really make sense; initialization starts _and_ finishes
with that method.

As such, this commit renames finish_initialization to just initialize.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* extension-priv.h (struct extension_language_ops): Rename
	'finish_initialization' to 'initialize'.
	* extension.c (finish_ext_lang_initialization): Renamed to...
	(ext_lang_initialization): ...this, update comment, and updated
	the calls to reflect the change in struct extension_language_ops.
	* extension.h (finish_ext_lang_initialization): Renamed to...
	(ext_lang_initialization): ...this.
	* guile/guile.c (gdbscm_finish_initialization): Renamed to...
	(gdbscm_initialize): ...this, update comment at definition.
	(guile_extension_ops): Update.
	* main.c (captured_main_1): Update call to
	finish_ext_lang_initialization.
	* python/python.c (gdbpy_finish_initialization): Rename to...
	(gdbpy_initialize): ...this, update comment at definition, and
	update call to do_finish_initialization.
	(python_extension_ops): Update.
	(do_finish_initialization): Rename to...
	(do_initialize): ...this, and update comment.

Now (thanks to the last few commits) all extension languages are
fully initialised in their finish_initialization method, this commit
delays the call to this method until after the early initialization
files have been processed.

Right now there's no benefit from doing this, but in a later commit I
plan to add new options for Python that will control how Python is
initialized.

With this commit in place, my next commits will allow the user to add
options to their early initialization file and alter how Python starts
up.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* main.c (captured_main_1): Add a call to
	finish_ext_lang_initialization.
	* top.c (gdb_init): Remove call to finish_ext_lang_initialization.

Like with the previous commit, this commit delays the initialisation
of the guile extension language until gdbscm_finish_initialization.

This is mostly about splitting the existing gdbscm_initialize_*
functions in two, all the calls to register_objfile_data_with_cleanup,
gdbarch_data_register_post_init, etc are moved into new _initialize_*
functions, but everything else is left in the gdbscm_initialize_*
functions.

Then the call to code previously in _initialize_guile is moved into
gdbscm_finish_initialization.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* guile/guile.c (gdbscm_set_backtrace): Add declaration.
	(gdbscm_finish_initialization): Add code moved from
	_initialize_guile.
	(_initialize_guile): Move code to gdbscm_finish_initialization.
	* guile/scm-arch.c (gdbscm_initialize_arches): Move some code into
	_initialize_scm_arch.
	(_initialize_scm_arch): New function.
	* guile/scm-block.c (gdbscm_initialize_blocks): Move some code
	into _initialize_scm_block.
	(_initialize_scm_block): New function.
	* guile/scm-frame.c (gdbscm_initialize_frames): Move some code
	into _initialize_scm_frame.
	(_initialize_scm_frame): New function.
	* guile/scm-objfile.c (gdbscm_initialize_objfiles): Move some code
	into _initialize_scm_objfile.
	(_initialize_scm_objfile): New function.
	* guile/scm-progspace.c (gdbscm_initialize_pspaces): Move some
	code into _initialize_scm_progspace.
	(_initialize_scm_progspace): New function.
	* guile/scm-symbol.c (gdbscm_initialize_symbols): Move some code
	into _initialize_scm_symbol.
	(_initialize_scm_symbol): New function.
	* guile/scm-symtab.c (gdbscm_initialize_symtabs): Move some code
	into _initialize_scm_symtab.
	(_initialize_scm_symtab): New function.
	* guile/scm-type.c (gdbscm_initialize_types): Move some code into
	_initialize_scm_type.
	(_initialize_scm_type): New function.

Delay Python initialisation until gdbpy_finish_initialization.

This is mostly about splitting the existing gdbpy_initialize_*
functions in two, all the calls to register_objfile_data_with_cleanup,
gdbarch_data_register_post_init, etc are moved into new _initialize_*
functions, but everything else is left in the gdbpy_initialize_*
functions.

Then the call to do_start_initialization (in python/python.c) is moved
from the _initialize_python function into gdbpy_finish_initialization.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* python/py-arch.c (_initialize_py_arch): New function.
	(gdbpy_initialize_arch): Move code to _initialize_py_arch.
	* python/py-block.c (_initialize_py_block): New function.
	(gdbpy_initialize_blocks): Move code to _initialize_py_block.
	* python/py-inferior.c (_initialize_py_inferior): New function.
	(gdbpy_initialize_inferior): Move code to _initialize_py_inferior.
	* python/py-objfile.c (_initialize_py_objfile): New function.
	(gdbpy_initialize_objfile): Move code to _initialize_py_objfile.
	* python/py-progspace.c (_initialize_py_progspace): New function.
	(gdbpy_initialize_pspace): Move code to _initialize_py_progspace.
	* python/py-registers.c (_initialize_py_registers): New function.
	(gdbpy_initialize_registers): Move code to
	_initialize_py_registers.
	* python/py-symbol.c (_initialize_py_symbol): New function.
	(gdbpy_initialize_symbols): Move code to _initialize_py_symbol.
	* python/py-symtab.c (_initialize_py_symtab): New function.
	(gdbpy_initialize_symtabs): Move code to _initialize_py_symtab.
	* python/py-type.c (_initialize_py_type): New function.
	(gdbpy_initialize_types): Move code to _initialize_py_type.
	* python/py-unwind.c (_initialize_py_unwind): New function.
	(gdbpy_initialize_unwind): Move code to _initialize_py_unwind.
	* python/python.c (_initialize_python): Move call to
	do_start_initialization to gdbpy_finish_initialization.
	(gdbpy_finish_initialization): Add call to
	do_start_initialization.

In order for our SIGINT handling to work correctly with Python we
require that SIGINT be set to SIG_DFL during Python's initialisation.

Currently this is the case, but, in a later commit I plan to delay the
initialisation of Python until after the point where GDB's own SIGINT
handler has been installed.

The consequence of this is that our SIGINT handling would become
broken.

In this commit I propose adding an RAII class that will ensure SIGINT
is set to SIG_DFL during the call to each extension languages
finish_initialization method.

At this point this change should have not effect.

gdb/ChangeLog:

	* extension.c (struct scoped_default_signal): New struct.
	(scoped_default_sigint): New typedef.
	(finish_ext_lang_initialization): Make use of
	scoped_default_sigint.

The argument to gdb_init is not used, remove it.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* main.c (captured_main_1): Don't pass argument to gdb_init.
	* top.c (gdb_init): Remove unused argument, and add header
	comment.
	* top.h (gdb_init): Remove argument.

PR gas/27763

While the comment in output_jump() was basically correct prior to the
introduction of 64-bit mode, both that and the not-JMP-like behavior of
XBEGIN require adjustments: Branches with 32-bit displacement do not
wrap at 4G in 64-bit mode, and XBEGIN with 16-bit operand size doesn't
wrap at 64k. Similarly %rip-relative addressing doesn't wrap at 4G.

The new testcase points out that for PE/COFF object_64bit didn't get
set so far, preventing in particular the check at the end of
md_convert_frag() to take effect.

For Mach-O the new testcase fails (bogusly), in that only the first two
of the expected errors get raised. Since for Mach-O many testcases
already fail, and since an x86_64-darwin target can't even be configured
for, I didn't think I need to bother.

Note that there are further issues in this area, in particular for
branches with operand size overrides. Such branches, which truncate
%rip / %eip, can't be correctly expressed with ordinary PC-relative
relocations. It's not really clear what to do with them - perhaps the
best we can do is to carry through all associated relocations, leaving
it to the linker (or even loader) to decide (once the final address
layout is known). Same perhaps goes for relocations associated with
32-bit addressing in 64-bit mode.