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.

MachOPlatformRuntimeState::lookupSymbols encapsulates the approach used in
dlsym in bb41fc68, but generalizes it to multiple symbols:
  1. try to resolve symbols locally
  2. issue a push-request for any unresolved symbols
  3. re-try local resolution

In the future lookupSymbols can serve as the basis for a public bulk lookup
API in the ORC runtime.

AFAICT, `ModuleFile::File` can be `std::nullopt` only for PCM files
loaded from the standard input. This patch starts setting that variable
to `FileManager::getSTDIN()` in that case, which makes it possible to
remove the optionality, and also simplifies code that actually reads the
file.

This is part of an effort to get rid of
`Optional{File,Directory}EntryRefDegradesTo{File,Directory}EntryPtr`.

Tries to simplify structural complexity of the findReusedOrderedScalars function.

[Flang][OpenMP][Semantics] Modify errors to warnings for semantic checks in IS_DEVICE_PTR related to list-items being dummy arguments. (#74370)

Changed semantic check from giving error to giving a warning about
deprecation from OpenMP 5.2 and later about checks for dummy argument
list-items present on IS_DEVICE_PTR clause.

This P is blocker for
https://github.com/llvm/llvm-project/pull/71255

Reapply llvm/llvm-project#72713 after fixing formatted printing of
`uint64_t` values as hex (see failing build here
https://lab.llvm.org/buildbot/#/builders/186/builds/13604).

This patch adds llvm-readobj support for:

- Dynamic `R_AARCH64_AUTH_*` relocations (including RELR compressed AUTH
relocations) as described here:
https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#auth-variant-dynamic-relocations

- `.note.AARCH64-PAUTH-ABI-tag` section as defined here
https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#elf-marking

This reverts the following commits:
 - a539a090
 - 31316b3f

Rationale for revert:
https://github.com/llvm/llvm-project/issues/74258#issuecomment-1847836861

https://github.com/llvm/llvm-project/pull/74764 reported that the
`lljit-with-remote-debugging` test fails on AArch64 hosts, because the
input IR file states arch x86_64 explicitly. In order to drop the target
triple we have to remove a check in the example implementation.

Not sure it's fully portable now, but at least it's better than before.

[RISCV][GISel] Re-generate legalize-vastart-rv32.mir and legalize-vastart-rv64.mir to fix buildbot failure. NFC

I must have messed something up when addressing feedback on the patch
that added these tests.

https://github.com/llvm/llvm-project/pull/74676 landed the work to
implement `-fdefine-target-os-macros` and enabled the extension for the
Darwin driver. However it is breaking some test builds. Leave the
extension disabled for now until we can fix/workaround the build
failures.

Note, tensor.empty may feed into SPARSE output (meaning it truly has no
values yet), but for a DENSE output, it should always have an initial
value. We ran a verifier over all our tests and this is the only
remaining omission.

On AIX, the __ehinfo toc-entry is never referenced directly using
instructions, therefore we can allocate them with the TE storage mapping
class to move them to the end of TOC.

The `< %s` needed to be removed. This change fixes the test introduced
in 02379d19

For BSR and convolutions, we encounter

(d0, d1, d2, d3) -> ((d0 + d2) floordiv 2, (d1 + d3) floordiv 2, (d0 +
d2) mod 2, (d1 + d3) mod 2)

which crashed the current test. Note that an actual test and working
code is still to follow (since we need to fix a few other things first)

Examle:

substitute
mesh.cluster @mesh0(rank = 2, dim_sizes = [0, 4])

with
mesh.cluster @mesh0(rank = 2, dim_sizes = ?x4)

Same as tensor/memref shapes. The only difference is for 0-rank shapes.
With tensors you would have something like `tensor<f32>`. Here to avoid
matching an empty string a 0-rank shape is denoted by `[]`.

This test is added to be the counterpart of the SelectionDAG
llvm/test/CodeGen/RISCV/vararg.ll test. Minor changes were made compared
to the other version, all which are commented in the test file added in
this commit.

This patch moves PassExecutionAction to Pass.h so that it can be used by
the action framework to introspect and intercede in pass managers that
might be set up opaquely. This provides for a very particular use case,
which essentially involves being able to intercede in a PassManager and
skip or apply individual passes. Because of this, this patch also adds a
test for this use case to verify that it could in fact work.

This removes some assumptions that the small code model will only
reference "near" globals.

There are still some missing optimizations and wrong code sequences, but
I'd like to address those separately. This will require auditing any
checks of the code model in the X86 backend.

We need to store the frame index to the location pointed to by the
VASTART, not the other way around.

In the future, we can consider adding a G_VACOPY opcode instead of going
through the GIntrinsic for all targets. We do the approach in this patch
because that is what other targets do today.

Add LL parsing for `<N x ty> splat(ty <imm>)` that lowers onto
ConstantInt::get() for integer types and ConstantFP::get() for
floating-point types.

The intent is to extend ConstantInt/FP classes to support vector types
rather than redirecting to other constant classes as the get() methods
do today.

This patch gives IR writers the convenience of using the shorthand
today, thus allowing existing tests to be ported.

When a tool defines only one or two subcommands, the `[subcommand]` part
is not displayed in the `USAGE` help line. Note that a similar issue
for printing the list of the subcommands has been fixed in
https://reviews.llvm.org/D25463.

This patch starts initial modeling of VF * UF in VPlan.
Initially, introduce a dedicated VFxUF VPValue, which is then
populated during VPlan::prepareToExecute. Initially, the VF * UF
applies only to the main vector loop region. Once we extend the
scope of VPlan in the future, we may want to associate different VFxUFs
with different vector loop regions (e.g. the epilogue vector loop)

This allows explicitly parameterizing recipes that rely on the
VF * UF, like the canonical induction increment. At the moment, this
mainly helps to avoid generating some duplicated calls to vscale with
scalable vectors. It should also allow using EVL as induction increments
explicitly in D99750. Referring to VF * UF is also needed in other
places that we plan to migrate to VPlan, like the minimum trip count
check during skeleton creation.

The first version creates the value for VF * UF directly in
prepareToExecute to limit the scope of the patch. A follow-on patch will
model VF * UF computation explicitly in VPlan using recipes.

Moved from Phabricator (https://reviews.llvm.org/D157322)

This fixes the macro syntax

Extends the lifetime of the map `ConstructedObjects` to be of the
whole CFG so that the map can connect temporary Ctor and Dtor in
different CFG blocks.