Integrate LLVM at llvm/llvm-project@a4d48e3b0b66
Integrate LLVM at llvm/llvm-project@a4d48e3b0b66

Updates LLVM usage to match
[a4d48e3b0b66](https://github.com/llvm/llvm-project/commit/a4d48e3b0b66)

PiperOrigin-RevId: 471850957

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