Changes

[mlir] Start splitting the `tensor` dialect out of `std`.

This starts by moving `std.extract_element` to `tensor.extract` (this
mirrors the naming of `vector.extract`).

Curiously, `std.extract_element` supposedly works on vectors as well,
and this patch removes that functionality. I would tend to do that in
separate patch, but I couldn't find any downstream users relying on
this, and the fact that we have `vector.extract` made it seem safe
enough to lump in here.

This also sets up the `tensor` dialect as a dependency of the `std`
dialect, as some ops that currently live in `std` depend on
`tensor.extract` via their canonicalization patterns.

Part of RFC: https://llvm.discourse.group/t/rfc-split-the-tensor-dialect-from-std/2347/2

Differential Revision: https://reviews.llvm.org/D92991

[flang] Removed an absolute path from the "flang" script

The "flang" script that gets put into "install/bin" had an absolute path
in it.  This precuded moving the install directory to a new location.

Differential Revision: https://reviews.llvm.org/D93131

Revert "[mlir] Start splitting the `tensor` dialect out of `std`."

This reverts commit cab8dda90f48e15ee94b0d55ceac5b6a812e4743.

I mistakenly thought that CAPI/ir.c failure was unrelated to this
change. Need to debug it.

[InstCombine][x86] fix insertion point bug in vector demanded elts fold (PR48476)

This transform was added at:
c63799fc52ff

From what I see, it's the first demanded elements transform that adds
a new instruction using the IRBuilder. There are similar folds in
the generic demanded bits chunk of instcombine that also use the
InsertPointGuard code pattern.

The tests here would assert/crash because the new instruction was
being added at the start of the demanded elements analysis rather
than at the instruction that is being replaced.

Revert "Revert "[mlir] Start splitting the `tensor` dialect out of `std`.""

This reverts commit 0d48d265db6633e4e575f81f9d3a52139b1dc5ca.

This reapplies the following commit, with a fix for CAPI/ir.c:

[mlir] Start splitting the `tensor` dialect out of `std`.

This starts by moving `std.extract_element` to `tensor.extract` (this
mirrors the naming of `vector.extract`).

Curiously, `std.extract_element` supposedly works on vectors as well,
and this patch removes that functionality. I would tend to do that in
separate patch, but I couldn't find any downstream users relying on
this, and the fact that we have `vector.extract` made it seem safe
enough to lump in here.

This also sets up the `tensor` dialect as a dependency of the `std`
dialect, as some ops that currently live in `std` depend on
`tensor.extract` via their canonicalization patterns.

Part of RFC: https://llvm.discourse.group/t/rfc-split-the-tensor-dialect-from-std/2347/2

Differential Revision: https://reviews.llvm.org/D92991

[libc] Let wrappergen pick LLVM libc mangled name from aliasee file.

Along the way, made a change to run tool unittests when the target
"check-libc" is run by introducing a libc testsuite for tool unittests.

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D93142

Store a MlirIdentifier instead of a MlirStringRef in MlirNameAttribute

This mirror the C++ API for NamedAttribute, and has the advantage or
internalizing earlier in the Context and not requiring the caller to
keep the StringRef alive beyong this call.

Differential Revision: https://reviews.llvm.org/D93133

[AIX][XCOFF] emit traceback table for function in aix

SUMMARY:
 1. added a new option -xcoff-traceback-table to control whether generate traceback table for function.
 2. implement the functionality of emit traceback table of a function.

Reviewers: hubert.reinterpretcast, Jason Liu
Differential Revision: https://reviews.llvm.org/D92398