Introduce "gdb/configure.nat" (and delete "gdb/config/*/*.mh" files)

Due to my ongoing work to make it possible for gdbserver to start the
inferior using the shell, I had to share the fork_inferior function
under the "nat/" directory.  In order to do that, I created a new file
and put the function there; however, this meant that I now had to
update some of the *.mh files (under "gdb/config") and add the new
file as a dependency to be built natively.  Bleh...

After talking a bit to Pedro about this, the idea came up to write a
new "gdb/configure.nat" file, a la "gdb/configure.tgt", which would
concentrate all of the native settings for each host/system.  I
decided to tackle this issue.

The patch is simple.  All of the previous Makefile variables that were
being declared inside the *.mh files are now inside "gdb/Makefile.in",
and "gdb/configure" is responsible for AC_SUBST'ing them.  The
definitions of these variables were put inside "gdb/configure.nat", so
now they're shell variables.  For excerpts of Makefile code, one must
create a file under "gdb/config/${gdb_cpu_host}" and reference it on
the "nat_extra_makefile_frag" variable.

It should now be easier to update the native dependencies of hosts in
this single file.

This has been tested on x86_64 without regressions.

gdb/ChangeLog:
2017-05-06  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in: Remove "@host_makefile_frag@".  Add variables
	NAT_FILE, NATDEPFILES, NAT_CDEPS, LOADLIBES, MH_CFLAGS, XM_CLIBS,
	NAT_GENERATED_FILES, HAVE_NATIVE_GCORE_HOST.  Add
	"@nat_extra_makefile_frag@".
	(Makefile): Remove dependency on "@frags@".
	($(GNULIB_BUILDDIR)/Makefile): Likewise.
	(data-directory/Makefile): Likewise.
	* config/aarch64/linux.mh: Deleted; moved contents to
	"gdb/configure.nat".
	* config/alpha/alpha-linux.mh: Likewise.
	* config/alpha/nbsd.mh: Likewise.
	* config/arm/linux.mh: Likewise.
	* config/arm/nbsdelf.mh: Likewise.
	* config/i386/cygwin.mh: Likewise.
	* config/i386/cygwin64.mh: Likewise.
	* config/i386/darwin.mh: Likewise.
	* config/i386/fbsd.mh: Likewise.
	* config/i386/fbsd64.mh: Likewise.
	* config/i386/go32.mh: Likewise.
	* config/i386/i386gnu.mh: Likewise.
	* config/i386/i386sol2.mh: Likewise.
	* config/i386/linux.mh: Likewise.
	* config/i386/linux64.mh: Likewise.
	* config/i386/mingw.mh: Likewise.
	* config/i386/mingw64.mh: Likewise.
	* config/i386/nbsd64.mh: Likewise.
	* config/i386/nbsdelf.mh: Likewise.
	* config/i386/nto.mh: Likewise.
	* config/i386/obsd.mh: Likewise.
	* config/i386/obsd64.mh: Likewise.
	* config/i386/sol2-64.mh: Likewise.
	* config/ia64/linux.mh: Likewise.
	* config/m32r/linux.mh: Likewise.
	* config/m68k/linux.mh: Likewise.
	* config/m68k/nbsdelf.mh: Likewise.
	* config/m68k/obsd.mh: Likewise.
	* config/m88k/obsd.mh: Likewise.
	* config/mips/fbsd.mh: Likewise.
	* config/mips/linux.mh: Likewise.
	* config/mips/nbsd.mh: Likewise.
	* config/mips/obsd64.mh: Likewise.
	* config/pa/linux.mh: Likewise.
	* config/pa/nbsd.mh: Likewise.
	* config/pa/obsd.mh: Likewise.
	* config/powerpc/aix.mh: Likewise.
	* config/powerpc/fbsd.mh: Likewise.
	* config/powerpc/linux.mh: Likewise.
	* config/powerpc/nbsd.mh: Likewise.
	* config/powerpc/obsd.mh: Likewise.
	* config/powerpc/ppc64-linux.mh: Likewise.
	* config/powerpc/spu-linux.mh: Likewise.
	* config/s390/linux.mh: Likewise.
	* config/sh/nbsd.mh: Likewise.
	* config/sparc/fbsd.mh: Likewise.
	* config/sparc/linux.mh: Likewise.
	* config/sparc/linux64.mh: Likewise.
	* config/sparc/nbsd64.mh: Likewise.
	* config/sparc/nbsdelf.mh: Likewise.
	* config/sparc/obsd64.mh: Likewise.
	* config/sparc/sol2.mh: Likewise.
	* config/tilegx/linux.mh: Likewise.
	* config/vax/nbsdelf.mh: Likewise.
	* config/vax/obsd.mh: Likewise.
	* config/xtensa/linux.mh: Likewise.
	* config/i386/i386gnu.mn: New file, with excerpts from
	"config/i386/i386gnu.mh".
	* configure: Regenerate.
	* configure.ac: Rewrite code to use "gdb/configure.nat" instead of
	*.mh files under "gdb/config".
	* configure.nat: New file, with contents from the
	"gdb/config/*/*.mh" files.

gdb/doc/ChangeLog:
2017-05-06  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile: Remove "@host_makefile_frag@".

7 files changed, 0 insertions, 75 deletions

diff --git a/gdb/config/powerpc/aix.mh b/gdb/config/powerpc/aix.mh
deleted file mode 100644
index 141501d..0000000
--- a/gdb/config/powerpc/aix.mh
+++ /dev/null
@@ -1,8 +0,0 @@
-# Host: IBM PowerPC running AIX
-
-# aix-thread.o is not listed in NATDEPFILES as it is pulled in by configure.
-NATDEPFILES= fork-child.o inf-ptrace.o rs6000-nat.o
-
-# When compiled with cc, for debugging, this argument should be passed.
-# We have no idea who our current compiler is though, so we skip it.
-# MH_CFLAGS = -bnodelcsect
diff --git a/gdb/config/powerpc/fbsd.mh b/gdb/config/powerpc/fbsd.mh
deleted file mode 100644
index 9c2e6b4..0000000
--- a/gdb/config/powerpc/fbsd.mh
+++ /dev/null
@@ -1,24 +0,0 @@
-#  Native config information for GDB on PowerPC systems running FreeBSD.
-#
-#  Copyright (C) 2013-2017 Free Software Foundation, Inc.
-#
-#  This file is part of GDB.
-#
-#  This program is free software; you can redistribute it and/or modify
-#  it under the terms of the GNU General Public License as published by
-#  the Free Software Foundation; either version 3 of the License, or
-#  (at your option) any later version.
-#
-#  This program is distributed in the hope that it will be useful,
-#  but WITHOUT ANY WARRANTY; without even the implied warranty of
-#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-#  GNU General Public License for more details.
-#
-#  You should have received a copy of the GNU General Public License
-#  along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-NATDEPFILES= fbsd-nat.o fork-child.o inf-ptrace.o ppc-fbsd-nat.o bsd-kvm.o
-HAVE_NATIVE_GCORE_HOST = 1
-
-LOADLIBES= -lkvm
-
diff --git a/gdb/config/powerpc/linux.mh b/gdb/config/powerpc/linux.mh
deleted file mode 100644
index f4a52c3..0000000
--- a/gdb/config/powerpc/linux.mh
+++ /dev/null
@@ -1,12 +0,0 @@
-# Host: PowerPC, running Linux
-
-XM_CLIBS=
-
-NAT_FILE= config/nm-linux.h
-NATDEPFILES= inf-ptrace.o fork-child.o \
-	ppc-linux-nat.o proc-service.o linux-thread-db.o \
-	linux-nat.o linux-osdata.o linux-fork.o linux-procfs.o linux-ptrace.o \
-	linux-waitpid.o linux-personality.o linux-namespaces.o
-NAT_CDEPS = $(srcdir)/proc-service.list
-
-LOADLIBES = -ldl $(RDYNAMIC)
diff --git a/gdb/config/powerpc/nbsd.mh b/gdb/config/powerpc/nbsd.mh
deleted file mode 100644
index f02a0f9..0000000
--- a/gdb/config/powerpc/nbsd.mh
+++ /dev/null
@@ -1,4 +0,0 @@
-# Host: NetBSD/powerpc
-NATDEPFILES= fork-child.o inf-ptrace.o ppc-nbsd-nat.o bsd-kvm.o
-
-LOADLIBES= -lkvm
diff --git a/gdb/config/powerpc/obsd.mh b/gdb/config/powerpc/obsd.mh
deleted file mode 100644
index 3743254..0000000
--- a/gdb/config/powerpc/obsd.mh
+++ /dev/null
@@ -1,4 +0,0 @@
-# Host: OpenBSD/powerpc
-NATDEPFILES= fork-child.o inf-ptrace.o obsd-nat.o ppc-obsd-nat.o bsd-kvm.o
-
-LOADLIBES= -lkvm
diff --git a/gdb/config/powerpc/ppc64-linux.mh b/gdb/config/powerpc/ppc64-linux.mh
deleted file mode 100644
index 8681d00..0000000
--- a/gdb/config/powerpc/ppc64-linux.mh
+++ /dev/null
@@ -1,15 +0,0 @@
-# Host: PowerPC64, running Linux
-
-XM_CLIBS=
-
-NAT_FILE= config/nm-linux.h
-NATDEPFILES= inf-ptrace.o fork-child.o \
-	ppc-linux-nat.o proc-service.o linux-thread-db.o \
-	linux-nat.o linux-osdata.o linux-fork.o linux-procfs.o linux-ptrace.o \
-	linux-waitpid.o ppc-linux.o linux-personality.o \
-	linux-namespaces.o
-NAT_CDEPS = $(srcdir)/proc-service.list
-
-# The dynamically loaded libthread_db needs access to symbols in the
-# gdb executable.
-LOADLIBES= -ldl $(RDYNAMIC)
diff --git a/gdb/config/powerpc/spu-linux.mh b/gdb/config/powerpc/spu-linux.mh
deleted file mode 100644
index 9205b62..0000000
--- a/gdb/config/powerpc/spu-linux.mh
+++ /dev/null
@@ -1,8 +0,0 @@
-# Target: Cell BE (PowerPC64 + SPU)
-
-# This implements a 'pseudo-native' GDB running on the
-# PPU side of the Cell BE and debugging the SPU side.
-
-NATDEPFILES = spu-linux-nat.o fork-child.o inf-ptrace.o \
-	      linux-procfs.o linux-ptrace.o linux-waitpid.o \
-	      linux-personality.o linux-namespaces.o