Integrate LLVM at llvm/llvm-project@ecfa87453113
Integrate LLVM at llvm/llvm-project@ecfa87453113

Updates LLVM usage to match
[ecfa87453113](https://github.com/llvm/llvm-project/commit/ecfa87453113)

PiperOrigin-RevId: 363495160

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