Integrate LLVM at llvm/llvm-project@625796f408cc
Integrate LLVM at llvm/llvm-project@625796f408cc

Updates LLVM usage to match
[625796f408cc](https://github.com/llvm/llvm-project/commit/625796f408cc)

PiperOrigin-RevId: 487240739

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