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

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/tonykuttai/pragma-comment-copyright-cli'.
Changed from e77eb2aea6fecba4bfa354fc9699ca04542f913b to e1229907e43007173f2c7222c4b1ad52e0860285
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 3bee38f3cbc87f392ea701a260d92dccfc2db621 by Tony Varghese on 06/08/2026 at 08:32..
[Clang][AIX] Preserve -mloadtime-comment-vars variables across serialization

Named internal-linkage variables were silently dropped when their
definition crossed a PCH or C++20 named-module (BMI-to-object) boundary:
DeclMustBeEmitted did not know the implicit attribute, so the PCH writer
never marked the unreferenced variable as required, and for named modules
only non-discardable variables are recorded in the module-initializer
lists that EmitModuleInitializers walks. Teach DeclMustBeEmitted about
the attribute (the CodeGen-side check becomes redundant and is removed)
and record validated internal-linkage module-purview variables in the
module-initializer list.

Since DeclMustBeEmitted now sees the attribute, a preserved variable no
longer triggers -Wunused-const-variable: it is materially used.

Add tests for C++20 module preservation, importer behavior, and
instantiation diagnostics; PCH preservation; unused-warning suppression;
the non-AIX cc1 no-op; and char8_t element-type exclusion. Document the
modules/PCH rules.
https://invent.kde.org/qt/clang/llvm/-/commit/3bee38f3cbc87f392ea701a260d92dccfc2db621

Git commit 269979b8937414a2cd54d9d43d74ada6e6eff625 by Tony Varghese on 06/08/2026 at 08:41..
nit: Minor updates to the comments
https://invent.kde.org/qt/clang/llvm/-/commit/269979b8937414a2cd54d9d43d74ada6e6eff625

Git commit e1229907e43007173f2c7222c4b1ad52e0860285 by Tony Varghese on 06/08/2026 at 09:50..
[Clang][AIX] Error on -mloadtime-comment-vars in cc1 for non-AIX targets

The driver continues to warn and drop the option for unsupported targets;
cc1, reachable directly or via -Xclang, now rejects it with
err_drv_unsupported_opt_for_target, mirroring the -mabi=quadword-atomics
and -mxcoff-roptr checks.
https://invent.kde.org/qt/clang/llvm/-/commit/e1229907e43007173f2c7222c4b1ad52e0860285