[clang] [PAC] Add support for __ptrauth type qualifier (PR #100830)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

I got through the rest of parser and sema, thank you for your patience! I think we should add quite a bit more testing for all the places where types are important in both C and C++; the test coverage we have right now is a good start, but misses a lot of the corner cases of the languages.

https://github.com/llvm/llvm-project/pull/100830