Simply mark `callx` as a valid ID, so it can be recognized.

Previously this valid asm triggers an error:

    # clang local/callx.s -target bpf
    local/callx.s:8:2: error: invalid register/token name
            callx r1
            ^

Without this patch, CallingConvLower.h is relying on the transitive
include of ArrayRef.h in TypeSize.h, which doesn't need ArrayRef.h.

These files are relying on the transitive include of <bitset> from
GIMatchTableExecutor.h, which doesn't actually use std::bitset.

hasExtension already checks if the extension is supported.

This patch renames {starts,ends}with to {starts,ends}_with for
consistency with std::{string,string_view}::{starts,ends}_with in
C++20.  Since there are only a handful of occurrences, this patch
skips the deprecation phase and simply renames them.

depend_diff_types.ll already covers the same tests afer it hs been
converted to opaque pointersj, so remove the redundant
depend_diff_types_opaque_ptr.ll

These functions have been deprecated since:

  commit 1117d806
  Author: Kazu Hirata <kazu@google.com>
  Date:   Mon Jun 5 13:18:07 2023 -0700

This patch introduces llvm-objdump tests for new `AARCH64_AUTH_RELR`,
`AARCH64_AUTH_RELRSZ` and `AARCH64_AUTH_RELRENT` dynamic tags.

Depends on https://github.com/llvm/llvm-project/pull/74874

Define HLSL's RasterizerOrderedBuffer resource type through the
external sema source. This doesn't fully work as is, but defining it
allows us to exercise the ROV logic in the DirectX backend from HLSL
rather than having to manually edit metadata, so it's useful for
further testing and development.

Pull Request: https://github.com/llvm/llvm-project/pull/74897

Query the executable for address size.

These names are never used so just waste a lot of memory. If do need
them ever, it would be better to store pointers to the StringMapEntry
objects that store the same strings.

Pull Request: https://github.com/llvm/llvm-project/pull/74896

An 8 bit bitfield should not have a preferred type of bool.

This fixes a clang-tidy diagnostic when building libc++ with RTTI
disabled. This was originally part of #65518.

Fixes regression introduced in b3e6ff33
Fixes bot failure https://lab.llvm.org/buildbot/#/builders/60/builds/15037
```
    .---command stderr------------
    | error: 'supported-warning' diagnostics seen but not expected:
    | File C:\buildbot\as-builder-1\x-armv7l\llvm-project\clang\test\SemaCXX\ms-constexpr-new.cpp Line 7: '__cdecl' calling convention is not supported for this target
    | 1 error generated.
    `-----------------------------
```

This adds the std.compat module. The patch contains a bit of refactoring
to avoid code duplication between the std and std.compat module.

Implements parts of
- P2465R3 Standard Library Modules std and std.compat

This change requires quite a number of changes in the tests; this is not
code I expect people to use in the wild. So I don't expect breakage for
users.

Implements:
- P2905R2 Runtime format strings, as a Defect Report

llvm-project/clang/lib/AST/ExprConstant.cpp:5645:74: error: '&&' within '||' [-Werror,-Wlogical-op-parentheses]
 5645 |       (Definition->isConstexpr() || Info.CurrentCall->CanEvalMSConstexpr &&
      |                                  ~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
 5646 |                                         Definition->hasAttr<MSConstexprAttr>()))
      |                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
llvm-project/clang/lib/AST/ExprConstant.cpp:5645:74: note: place parentheses around the '&&' expression to silence this warning
 5645 |       (Definition->isConstexpr() || Info.CurrentCall->CanEvalMSConstexpr &&
      |                                                                          ^
      |                                     (
 5646 |                                         Definition->hasAttr<MSConstexprAttr>()))
      |
      |                                                                               )
1 error generated.

This commit introduces support for the MSVC-specific C++11-style
attribute `[[msvc::constexpr]]`, which was introduced in MSVC 14.33.
The semantics of this attribute are enabled only under
MSVC compatibility (`-fms-compatibility-version`) 14.33 and higher.
Additionally, the default value of `_MSC_VER` has been raised to 1433.

The current implementation lacks support for:
- `[[msvc::constexpr]]` constructors (see #72149);
  at the time of this implementation, such support would have required
  an unreasonable number of changes in Clang.
- `[[msvc::constexpr]] return ::new` (constexpr placement new) from
  non-std namespaces (see #74924).

Relevant to: #57696

This patch continues the work started with ea5b1ef0. See that commit and its
corresponding PR for details.

Alive2: https://alive2.llvm.org/ce/z/38KiC_

Invert the logic and choose the ELF path by default as a fallback. Move
check for Darwin to the top.

These both do the same thing, but some profiling on a
Releast+Asserts build suggests isRVVSizelessBuiltinType() is the
more efficient version so lets keep that one.