[llvm] [Dwarf] Support `__ptrauth` qualifier (PR #82363)

[Daniil Kovalev via llvm-commits]

kovdan01 wrote:

This applies the following commit https://github.com/ahmedbougacha/llvm-project/commit/857fcbda9529be8d32b357dcf3ac0d2a90319365 with a couple of fixes:
- fix of incorrect usage of `std::optional<bool>` used to store the address discrimination flag https://github.com/access-softek/llvm-project/commit/a34910a6e58f4c441b1ef314898308720542ce6c
- fix of `SubclassData32` usage: it's used for signing schema, but since https://github.com/llvm/llvm-project/commit/102f7fce8d8251655be5bf6955af33e55bea9c9e it's also used for alignment


https://github.com/llvm/llvm-project/pull/82363