Integrate LLVM at llvm/llvm-project@277f86d61069
Integrate LLVM at llvm/llvm-project@277f86d61069

Updates LLVM usage to match
[277f86d61069](https://github.com/llvm/llvm-project/commit/277f86d61069)

PiperOrigin-RevId: 415135398

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