[qt/clang/llvm-project]: Summary of bulk changes made

Git repository change summary for qt/clang/llvm-project
Pushed by mirror-service into branch 'upstream/release/23.x'.
Changed from 47e2df730a099583f16fc6fe64f0d2ffc5b7a16a to 278c31bfb8ceb7ea17dbfd11a4fb21e6634af957
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit 033aa122e399ba23d216fa3e469ee62721b1b8e7 by Douglas Yung (on behalf of Ikhlas Ajbar) on 17/07/2026 at 17:33..
[Hexagon] Fix HexagonRDFOpt hang during live-in recomputation (#209986)

After HexagonRDFOpt, the compiler recomputed live-in registers for every
block in one batch. On large inputs (e.g. kernel builds) this was slow,
and on some functions each pass changed the live-in values of other
blocks, triggering more passes until the compiler hung (PR #207422).

Fix: process blocks one at a time in post-order (successors before
predecessors) and stop as soon as nothing changes. Add a pass limit as a
safety net to keep compile time bounded in all cases.

(cherry picked from commit da6f3e6cc2565e4c6cf720931845c8eee132ce86)
https://invent.kde.org/qt/clang/llvm-project/-/commit/033aa122e399ba23d216fa3e469ee62721b1b8e7

Git commit 52cbf59a5085bff2083a03a71bfbd82b882b024a by Douglas Yung (on behalf of maflcko) on 17/07/2026 at 17:34..
[compiler-rt][ubsan] Fix suppressions for inlined functions (#206735)

Align suppression PC handling with getCallerLocation(), so function
suppressions identify the inlined function that caused a report.

Intentionally match only the innermost inline frame.

Extend suppressions-nested-calls.c coverage to -O1.

Fixes https://github.com/llvm/llvm-project/issues/209501

---------

Co-authored-by: MarcoFalke <*~=`'#}+{/-|&$^[email protected]>
(cherry picked from commit a376783e2ed3a44f63991c97513711faad09525b)
https://invent.kde.org/qt/clang/llvm-project/-/commit/52cbf59a5085bff2083a03a71bfbd82b882b024a

Git commit 44addbd4e1fbf754092185cd74c08a1e283df80f by Douglas Yung (on behalf of Nikita Popov) on 17/07/2026 at 17:35..
[LTO] Sort DefinedGlobals in LTO cache key (#210025)

Sort the DefindeGlobals by GUID when computing the LTO cache key, to
avoid making the cache key dependent on the insertion order. This fixes
large compile-time regressions in rust incremental builds.

Alternatively one could make collectDefinedGVSummariesPerModule() work
on the sortedRange(), but as that is also used in other places, it
probably makes sense to sort locally.

The issue was introduced in 760bb06cb3cd98832f1e4e7a4eaebd98b66d2bdd.

(cherry picked from commit 90e31c46d005ae0a7f5968c38a9310bee499923c)
https://invent.kde.org/qt/clang/llvm-project/-/commit/44addbd4e1fbf754092185cd74c08a1e283df80f

Git commit 28af770db4db6f04d047f52e7e135386fe7a6824 by Douglas Yung (on behalf of cqwrteur) on 17/07/2026 at 17:36..
[libcxx] avoid include Uppercase windows headers (#208903)

We should use unknwn.h and windows.h instead of Unknwn.h and Windows.h
because Linux and other non‑Windows systems treat filenames as
case‑sensitive. Windows does not, so mixed‑case includes work there but
break elsewhere. Both mingw‑w64‑crt and windows‑msvc‑sysroot provide all
Windows headers in fully lowercase, so using the lowercase forms ensures
consistent cross‑platform builds.

Fixes #208901

(cherry picked from commit 2580624091e36b85c162439513eef8e752217a1d)
https://invent.kde.org/qt/clang/llvm-project/-/commit/28af770db4db6f04d047f52e7e135386fe7a6824

Git commit 44727f2bc6e66afccfc0e3e3f0d2e5f241924593 by Douglas Yung (on behalf of Jacek Caban) on 17/07/2026 at 17:36..
[clang][mingw] Try both native and ARM64EC triples when looking for a sysroot on the ARM64EC target (#210017)

Similarly to MSVC, a MinGW toolchain may provide support for both ARM64
and ARM64EC in a single sysroot. Structuring the toolchain this way has
the additional advantage of seamlessly supporting linking ARM64X images.

Support this configuration in findClangRelativeSysroot.

(cherry picked from commit 205a66201235c03b892e075ae548d6ea12f024a3)
https://invent.kde.org/qt/clang/llvm-project/-/commit/44727f2bc6e66afccfc0e3e3f0d2e5f241924593

Git commit f83ba9d97b34021e3d2ff2faf7b04a3001b2c7ca by Douglas Yung (on behalf of Nikita Popov) on 17/07/2026 at 17:37..
[X86] Fix assertion failure for tail call on i686+pic (#210302)

The pattern for TCRETURNmi has a IsNotPIC predicate, but the
checkTCRetEnoughRegs() predicate that's part of the X86tcret_enough_regs
PatFrag is evaluated first, so we can't assert that PIC is disabled
here. We should just return false in that case.

Fixes https://github.com/llvm/llvm-project/issues/210300.

(cherry picked from commit 23b0281d75a4320a4e6e3d837edf94911d98d252)
https://invent.kde.org/qt/clang/llvm-project/-/commit/f83ba9d97b34021e3d2ff2faf7b04a3001b2c7ca

Git commit 278c31bfb8ceb7ea17dbfd11a4fb21e6634af957 by Douglas Yung (on behalf of Tom Stellard) on 17/07/2026 at 17:38..
workflows: Fixes for release-binaries and upload-release-artifact (#209246)

There were some bugs in upload-release-artifact workflow and
release-binaries was not including this action in its checkout.

(cherry picked from commit 963e226d9a6b923b10c8e328438838bd42e03d18)
https://invent.kde.org/qt/clang/llvm-project/-/commit/278c31bfb8ceb7ea17dbfd11a4fb21e6634af957