Integrate LLVM at llvm/llvm-project@8a7c657c4d65
Integrate LLVM at llvm/llvm-project@8a7c657c4d65

Updates LLVM usage to match
[8a7c657c4d65](https://github.com/llvm/llvm-project/commit/8a7c657c4d65)

PiperOrigin-RevId: 389614352

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