When the orphan section is placed after i, incrementing then
decreamenting is quite difficult to understand. Simplify the code to a
single loop to make the intention clearer.

Simplify the loop that considers sections of the same proximity. The two
involved conditions are due to:

* https://reviews.llvm.org/D111717 ("[ELF] Avoid adding an orphan section to a less suitable segment") and
* https://reviews.llvm.org/D112925 ("[ELF] Better resemble GNU ld when placing orphan sections into memory regions")

Our pattern previously checked for the merge operand being undef.

These either have an explicit policy operand or use TU policy.

Reverts llvm/llvm-project#92843 because it broke some lldb tests:

https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-linux-x64/b8746385730949743489/overview

- Prevent null dereference: if the Mask given to
  `ShuffleInstructionBuilder::adjustExtracts()` is empty or all-poison,
  then `VecBase` will be `nullptr` and the call to
  `castToScalarTyElem(VecBase)` will dereference it. Add an assert
  to guard against this.

- Prevent use of uninitialized scalar: in the unlikely event that
  `CandidateVFs` is empty, then `AnyProfitableGraph` will be
  uninitialized in `if` condition following the loop. (This seems like a
  false-positive, but I submitted this change anyways as initializing
  bools costs nothing and is generally good practice)

The -all_load flag is intended to force the linker to load all lazy members, but doesn't do so if the archive is specified with --start-lib, --end-lib flags. The `-all_load` flag is global, that is it can be placed anywhere in the linker invocation, and it affects the load behavior of all conventional archives listed. Unlike ELF's --whole-archive, the user need not necessarily have access to the entire linker invocation to reasonably make use of the flag. The user can supply `-all_load` to a build system without inspecting the rest of the linker invocation.

To make the behavior of `--start-lib` style archives consistent with regular archives, this patch makes it so that -all_load also applies in this case.

Protect against nullptr after #93926

bolt/test/lit.local.cfg wants to use the system GCC installation but it
specifies a wrong triple ("linux" instead of "linux-gnu") and relies on
clangDriver's loose GCC installation detection to pick up "*-linux-gnu".

This loose behavior may not work. Use "linux-gnu" instead.

Note: neither "linux" nor "linux-gnu" detects "linux-musl" triples, so
these tests currently fail on musl based systems.

Other files changes are cosmetic.

- Fix check after cab81dd0

This patch introduces memprof::LinearFrameId, which is a frame version
of memprof::LinearCallStackId.

Remove double escape characters before a RUN in a test.

Remove double escape characters before a RUN in a test.

Adds DWARF4 and DWARF5 tests with multiple CUs.

Added double escape characters to lines that describe a test.

# Changes

1. Changes to the structured transcript.
1. Add fields `commandName` and `commandArguments`. They will hold the
name and the arguments string of the expanded/executed command (e.g.
`breakpoint set` and `-f main.cpp -l 4`). This is not to be confused
with the `command` field, which holds the user input (e.g. `br s -f
main.cpp -l 4`).
2. Add field `timestampInEpochSeconds`. It will hold the timestamp when
the command is executed.
3. Rename field `seconds` to `durationInSeconds`, to improve
readability, especially since `timestampInEpochSeconds` is added.
2. When transcript is available and the newly added option
`--transcript` is present, add the transcript to the output of
`statistics dump`, as a JSON array under a new field `transcript`.
3. A few test name and comment changes.

This patch replaces uint32_t with LinearCallStackId where appropriate.
I'm replacing uint64_t with LinearCallStackId in
writeMemProfCallStackArray, but that's OK because it's a value to be
used as LinearCallStackId anyway.

https://github.com/llvm/llvm-project/commit/0e96eebc7f681a7ce41f35909e609c7c61a11455
accidentally turned the prior patch
(https://github.com/llvm/llvm-project/commit/57a507930b50c445140feb68bffe1c21af53319e)
into a no-op because this macro is always defined (as either 1 or 0).
This patch changes it to correctly use #if.

This adds codegen support for the "ptrauth" operand bundles, which can
be used to augment indirect calls with the equivalent of an
`@llvm.ptrauth.auth` intrinsic call on the call target (possibly
preceded by an `@llvm.ptrauth.blend` on the auth discriminator if
applicable.)

This allows the generation of combined authenticating calls
on AArch64 (in the BLRA* PAuth instructions), while avoiding
the raw just-authenticated function pointer from being
exposed to attackers.

This is done by threading a PtrAuthInfo descriptor through
the call lowering infrastructure, eventually selecting a BLRA
pseudo.  The pseudo encapsulates the safe discriminator
computation, which together with the real BLRA* call get emitted
in late pseudo expansion in AsmPrinter.

Note that this also applies to the other forms of indirect calls,
notably invokes, rvmarker, and tail calls.  Tail-calls in particular
bring some additional complexity, with the intersecting register
constraints of BTI and PAC discriminator computation.
However this doesn't currently support PAuth_LR tail-call variants.

This also adopts an x8+ allocation order for GPR64noip, matching
GPR64.

Follow up to #93881. Updates missed tests and handles `_Dmain`.

According to LLVM style guide, we prefer putting the documentation
comments for public APIs into the header file.

See
https://llvm.org/docs/CodingStandards.html#doxygen-use-in-documentation-comments
for more details.

This is the current key assignment defined by the arm64e architecture
on Darwin platforms, and also matches the intended key assignments
in the initial ELF adopters.  This can be made more generic if needed,
by e.g., defining these in the preprocessor instead.

Move EntryExitInstrumenter(PostInlining=true) to as late as possible and
EntryExitInstrumenter(PostInlining=false) to an early pre-inlining stage
(but skip for ThinLTO post-link).

This should fix the issues reported in
https://github.com/rust-lang/rust/issues/92109 and
https://github.com/llvm/llvm-project/issues/52853. These are caused
by https://reviews.llvm.org/D97608.

I apparently missed a few other clauses as well when doing my initial
implementation, so this adds tests for all, and fixes up the few that
had problems.

This is something that I'll do better to keep an eye on, though
shouldn't be necessary once the rest of the clauses are implemented and
we can remove the 'default' case.

Summary:
Currently we just print the error as seen, this makes it difficult if
something goes wrong to know where it failed. This patch just adds in
line numbers to all the error handling routines so you can trace it
back.

Currently it is only supported for FLAT Global.

The C intrinsics should allow a value to be specified for the upper
elements.

This used to work before https://reviews.llvm.org/D146752 which should
have only changed the behavior for the autovectorizer. It clearly
changed all reductions.

The function has been deprecated since:

  commit f9306f6d
  Author: Kazu Hirata <kazu@google.com>
  Date:   Tue Oct 24 23:03:13 2023 -0700

Rebased over https://github.com/llvm/llvm-project/pull/93243



Co-authored-by: Jeremy Kun <j2kun@users.noreply.github.com>

Currently, with PIC relocatable links, FatLTO sections are treated as
orphan
sections and incorrectly concatenated together. This test verifies the
current
behavior, but should be fixed to either merge those sections into a
single llvm
module, similar to what `llvm-link` would produce, or to drop them
altogether.

Removed mutability from BB::LayoutIndex, subsequently removed const from
BB::SetLayout, and changed BF::dfs to track visited blocks with a set as
opposed to tracking and altering LayoutIndexes for more consistent code.