This commit introduces a shared library for the MLIR execution engine.
This library is only built when `LLVM_BUILD_LLVM_DYLIB` is set. Having
such a library allows downstream users to depend on the execution engine
without giving up dynamic linkage. This is especially important for CPU
runner style tools, as they link against large parts of MLIR and LLVM.

Introduce `Decl::isFromExplicitGlobalModule` to replace the
`D->getOwningModule() && D->getOwningModule()->isExplicitGlobalModule()`
pattern to save some typings.

Found with -Wundefined-func-template.

apx-spec: https://cdrdv2.intel.com/v1/dl/getContent/784266
apx-syntax-recommendation:
https://cdrdv2.intel.com/v1/dl/getContent/817241

Revert "Reapply "[clang][nullability] allow _Nonnull etc on nullable class types (#82705)"" (#87041)

This reverts commit bbbcc1d9.

This change is causing the following build bots to fail due to a missing
header file:
- https://lab.llvm.org/buildbot/#/builders/188/builds/43765
- https://lab.llvm.org/buildbot/#/builders/176/builds/9428
- https://lab.llvm.org/buildbot/#/builders/187/builds/14696
- https://lab.llvm.org/buildbot/#/builders/186/builds/15551
- https://lab.llvm.org/buildbot/#/builders/182/builds/9413
- https://lab.llvm.org/buildbot/#/builders/245/builds/22507
- https://lab.llvm.org/buildbot/#/builders/258/builds/16026
- https://lab.llvm.org/buildbot/#/builders/249/builds/17221
- https://lab.llvm.org/buildbot/#/builders/38/builds/18566
- https://lab.llvm.org/buildbot/#/builders/214/builds/11735
- https://lab.llvm.org/buildbot/#/builders/231/builds/21947
- https://lab.llvm.org/buildbot/#/builders/230/builds/26675
- https://lab.llvm.org/buildbot/#/builders/57/builds/33922
- https://lab.llvm.org/buildbot/#/builders/124/builds/10311
- https://lab.llvm.org/buildbot/#/builders/109/builds/86173
- https://lab.llvm.org/buildbot/#/builders/280/builds/1043
- https://lab.llvm.org/buildbot/#/builders/283/builds/440
- https://lab.llvm.org/buildbot/#/builders/247/builds/16034
- https://lab.llvm.org/buildbot/#/builders/139/builds/62423
- https://lab.llvm.org/buildbot/#/builders/216/builds/36718
- https://lab.llvm.org/buildbot/#/builders/259/builds/2039
- https://lab.llvm.org/buildbot/#/builders/36/builds/44091
- https://lab.llvm.org/buildbot/#/builders/272/builds/12629
- https://lab.llvm.org/buildbot/#/builders/271/builds/6020
- https://lab.llvm.org/buildbot/#/builders/236/builds/10319

We can avoid libcalls.

Fixes #86205

This is the second attempt of 32fcfcdc,
which had to be reverted.

This should be good to go now, after a number of cleanups to not expose
headers from multiple targets:

- 6e58efac
- f1dff836
- 89ef3130
- eb70b485
- 83e5a123
- fce046ca

by default

For reduced BMI, it is meaningless to record the local declarations in
functions if not required explicitly during the process of writing the
function bodies.

It wastes time for reduced BMI and may be problematic if we want to
avoid transiting unnecessary changes.

This patch adds the nuw (no unsigned wrap) and nsw (no signed wrap)
poison-generating flags to the trunc instruction.

Discourse thread:
https://discourse.llvm.org/t/rfc-add-nowrap-flags-to-trunc/77453

This adds the ability to create a Scalar from an APFloat, and to create
an APFloat from an APSInt or another APFloat.

We currently check if the source and promoted types are not equal before
generating truncate instructions. This does not work for RV64 where the
promoted type is i64 and this lead to a crash due to the generation of
truncate instructions from i32 to i64.

Fixes #86400

size_t in PatchItem eliminates the need for casts.

Move all the stale profile matching stuffs into new files so that it can
be shared for unit testing.

In python3.11 there is a new environment variable PYTHONSAFEPATH which
stops python from setting the current directory as the first entry in
sys.path. Bazel started setting this to ensure that python targets
don't accidentally access things that aren't in their dependency tree.
This resulted in lit tests breaking because sys.path didn't include the
directory to the lit source files. This is fixed by adding the lit
binary to the dependency tree and propagating the import path from it.

Fixes https://github.com/llvm/llvm-project/issues/75963

Also another move comment to correct place.

represented by bitwidth without analysis.

Need to check that initial ext/trunc nodes can be safely represented
using calculated bitwidth before applying it.

node.

In the StackDepot::isValid function, there is work to validate the
TabMask variable. Unfortunately, if TabMask is set to the maximum
allowed value, TabSize = TabMask + 1 becomes zero and validation passes.

Disallow that case to prevent invalid reads into the Tab structure.

This is a follow-up to the profile format change in https://github.com/llvm/llvm-project/pull/82711

- Add pointers to code for source of truth.
- Move necessary details from doc to code.

Our CI system makes the source tree read-only. The 'cp' command that
copies a directory from the source tree into a temp directory preserves
permissions, and the copied files stay read-only. When the test tries to
append to one of these files, it fails with a "permission denied" error.

I tried to add representative tests while not duplicating complete
coverage.  If there's other tests you'd like to see, let me know.

This reverts commit ca4c4a67.

This was intended not to introduce new consistency diagnostics for
smart pointer types, but failed to ignore sugar around types when
detecting this.
Fixed and test added.

General cleanup in LangRef (and two outdated comments in LLParser.cpp)
with the aim of making it easier to understand some of the terminology
and subtle idiosyncrasies related to metadata in the IR.

I'm still not happy with the fact that "node" is used both informally
and with a particular category of metadata in mind, depending on the
context. This also bleeds into the type names in the implementation.

There are also several places where names from the implementation appear
in the document with no other context or definition. In some cases I
added a parenthetical to section titles to tie the two together, but I
don't think this is ideal.

I also think it might be useful to define the "abstract" metadata
classes like "DIScope" in the document, so the hierarchy of metadata
node kinds is direct, and so we can avoid repetitive descriptions of all
of the members of on part of the hierarchy. This inheritance doesn't
have to be in terms of C++ classes, but using the same names as the
implementation seems helpful, and we already do it for many other
things.

Finally I added sections for the specialized nodes which are implemented
in the IR but didn't have documentation in LangRef yet. These could use
some work, and I admit I didn't dig too deep into the specifics beyond
enumerating the fields, but I think we would ideally always have a
LangRef section for every kind of node.

This can be adjusted during runtime and it may impact the memory
footprint if it's set to a big value or is disabled.

Adds tests for `inf` and `nan` values to the tests for `strfrom*()`
functions.

Also marks some variables as `[[maybe_unused]]` to silence unused
variable warnings.

libc++ debug mode verifies that a comparator passed to std::sort defines
a strict weak order by calling it with the same element.

See also:

- RFC that introduced the feature:
  https://discourse.llvm.org/t/rfc-strict-weak-ordering-checks-in-the-debug-libc/70217

- `strict_weak_ordering_check.h` in libc++ sources.

Fixes #86917

`FCMP_TRUE` and `FCMP_FALSE` were previously not considered and we ended
up in an llvm_unreachable assertion.

This narrows unsigned and signed div and rem nodes via
combineBinOpOfZExt.

Unlike other binary ops, there are no widening div or rem instructions.
So we will end up with an extra vzext.vf2.

However I'm assuming that div/rem are expensive enough that by reducing
their EMUL we will gain back the cost.

Alive2 proof: https://alive2.llvm.org/ce/z/Et_L6y

swifttailcc is a new calling convention in LLVM introduced in
https://reviews.llvm.org/D95443. We add a new DWARF tag to capture
this in debuginfo.

Differential Revision: https://reviews.llvm.org/D95704

[Note: This patch seems to have been forgotten about, landing it now with considerable delay]

Previously we wouldn't remove dead copies from basic blocks with
successors. The comment said we didn't want to trust the live-in lists.
The comment is very old so I'm not sure if that's still a concern today.

This patch checks the live-in lists and removes copies from
MaybeDeadCopies if they are referenced by any live-ins in any
successors. We only do this if the tracksLiveness property is set. If
that property is not set, we retain the old behavior.

Add lowering of `llvm.bitreverse` and `llvm.trunc` intrinsics to DXIL
ops.

Fixes #86582
Fixes #86581

This reverts commit 7c1c07c9.

Fails in presubmit.

Link: https://lab.llvm.org/buildbot/#/builders/90/builds/67461
Link: https://lab.llvm.org/buildbot/#/builders/225/builds/33519
Link: https://lab.llvm.org/buildbot/#/builders/163/builds/53858
Link: https://lab.llvm.org/buildbot/#/builders/250/builds/20983
Link: #86924

This patch adds a version field to the MemProf section of the indexed
profile format, calling the new version "version 1".  The existing
version is called "version 0".

The writer supports both versions via a command-line option:

  llvm-profdata merge --memprof-version=1 ...

The reader supports both versions by automatically detecting the
version from the header.

This patch fixes:

  llvm/lib/Target/SystemZ/SystemZISelLowering.cpp:8181:9: error:
  unused variable 'TFL' [-Werror,-Wunused-variable]

The helper now only deals with live-ins, clarify the name.

The commit 8bed754c was intended to
support the use case where users want to run all the LLDB tests in an
environment where pexpect is not installed. Those users can build with
`-DLLDB_TEST_USER_ARGS=--skip-category=pexpect` to skip pexpect tests,
*but* because we still fail in cmake configuration, they must use
`-DLLDB_TEST_USE_VENDOR_PACKAGES=ON` to avoid failing due to pexpect not
being available.

I would like to remove `LLDB_TEST_USE_VENDOR_PACKAGES` now, but first
I'd like to make sure users w/o pexpect can pass CI with
`-DLLDB_TEST_USE_VENDOR_PACKAGES=OFF
-DLLDB_TEST_USER_ARGS=--skip-category=pexpect`. Once that is done, I am
not aware of any other issues caused by the previous commits, so the
third party tree should be safe to remove.

Updates the special case of pseudo infinty as pointed in #85940

lld/test/MachO/objc-relative-method-lists-simple.s fails on AArch64
hosts running 32-bit ARM binaries, such as
armv8l-unknown-linux-gnueabihf.

Disable the test on the failing targets for now, to keep the
buildbots passing.