[clang] [Clang] [Sema] Handle `this` in `__restrict`-qualified member functions properly (PR #83187)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman approved this pull request.

LGTM! I think the other work should be done in a follow-up patch as it is slightly different than this fix.

https://github.com/llvm/llvm-project/pull/83187