[clang] [Clang] Fix template elision to preserve qualifiers in diagnostics (PR #180175)

[Corentin Jabot via cfe-commits]

https://github.com/cor3ntin commented:

This change needs a release note.
Please add an entry to `clang/docs/ReleaseNotes.rst` in the section the most adapted to the change, and referencing any Github issue this change fixes. Thanks!

This also needs tests - did you run existing tests? I am surprised none would break.

https://github.com/llvm/llvm-project/pull/180175