Integrate LLVM at llvm/llvm-project@628f5c9da29b
Integrate LLVM at llvm/llvm-project@628f5c9da29b

Updates LLVM usage to match
[628f5c9da29b](https://github.com/llvm/llvm-project/commit/628f5c9da29b)

PiperOrigin-RevId: 363858631

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