Integrate LLVM at llvm/llvm-project@c50faffb4eec
Integrate LLVM at llvm/llvm-project@c50faffb4eec

Updates LLVM usage to match
[c50faffb4eec](https://github.com/llvm/llvm-project/commit/c50faffb4eec)

PiperOrigin-RevId: 393825475

google-research/structured-additive-IR,google-research/structured-additive-IR