[clang] [llvm] [Support] Add SipHash-based 16/64-bit ptrauth stable hash. (PR #93902)

[Daniil Kovalev via cfe-commits]

https://github.com/kovdan01 commented:

As far as I understand, we want to take reference SipHash implementation with minimal changes. I personally have no issues with taking cryptographic C code "as is" with minimal changes. If it is the intention, LGTM with several minor comments.

Anyway, I want someone else with deeper understanding of the context to take a look before this gets merged.

https://github.com/llvm/llvm-project/pull/93902