[llvm] [PtrAuth] Add ConstantPtrAuth comparator to FunctionComparator.cpp (PR #159480)

[Anatoly Trosinenko via llvm-commits]

https://github.com/atrosinenko commented:

Thank you for all the updates!

The PR description seems to be out of sync with the latest patch, as `ptrauth-const-compare.ll` has many synthetic test cases now.

https://github.com/llvm/llvm-project/pull/159480