[llvm] [DRAFT][BOLT] runtime: syscall wrappers cleanup (PR #207190)

[via llvm-commits]

DmitriiMartynov wrote:

Hi @aaupov @paschalis-mpeis 

Please take a look at the draft PR (will be split into several PRs later).
The main idea is to use syscall wrappers from LLVM's libc source code instead of the BOLT custom ones.
If this looks good from your point of view, I'll continue with the cleanup.

https://github.com/llvm/llvm-project/pull/207190