[clang] [clang-tools-extra] thread-safety: Support the new capability-based names for all related attributes. (PR #99919)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> > Thank you for these changes! Can you also add a release note to `clang/docs/ReleaseNotes.rst` so users know about the new attribute spellings?
> 
> They are already sort of documented as such – but will update the ReleaseNotes.rst.
> 
> Does anyone know why the new names were documented but not actually implemented?

I think this was my oversight -- I can't find any discussion where we intentionally made a decision to do this. CC @delesley who also worked on this at the same time.

https://github.com/llvm/llvm-project/pull/99919