[llvm] [BOLT][AArch64] Support for pointer authentication (PR #117578)

[Paschalis Mpeis via llvm-commits]

https://github.com/paschalis-mpeis commented:

Thanks for your PR @bgergely0. This seems a long awaited feature! 🎉 

Some higher-level notes:
- IMHO the patch is somewhat big and maybe it could be broken down to separate PRs, like the `populateFunctionNames`, or the introduction of the `no-returns` flags, the creation of `getCalleeName`, etc, then followed by a PR with the pass itself.
- you could expand/add descriptions to the pass and to related functions. You've added a very nice introduction to your PR, I was thinking of something equivalent to relevant places in code.

Apart form that, I've added some nits/reformatting comments and a concern whether the pass should run a bit earlier. Good stuff!

https://github.com/llvm/llvm-project/pull/117578