[clang] [clang][bytecode] Use tailcalls via `[[clang::musttail]]` (PR #173756)

[Timm Baeder via cfe-commits]

tbaederr wrote:

The new version uses a loop on MSVC + debug and if none of the checked musttail attributes are available.

Quick perf comparison:
<img width="1040" height="190" alt="Screenshot From 2026-03-10 05-57-38" src="https://github.com/user-attachments/assets/4e1bf97d-e326-4cf9-ac7b-379444f81909" />

The current check for the MSVC case is `(defined(_MSVC) && defined(_DEBUG))`. I have no idea if that is correct and no way to test though.

https://github.com/llvm/llvm-project/pull/173756