[llvm] [BOLT][WIP] Support restartable sequences in tcmalloc (PR #157774)

[Maksim Panchenko via llvm-commits]

maksfb wrote:

Thanks for trying the patch out. I'm going to look more into it and specifically at the warnings. Meanwhile, I've updated the patch to ignore the `__rseq-cs`-referenced functions completely, you can try it and it should work without the need for `--skip-funcs=...`.

https://github.com/llvm/llvm-project/pull/157774