Integrate LLVM at llvm/llvm-project@ef76686916d4
Integrate LLVM at llvm/llvm-project@ef76686916d4

Updates LLVM usage to match
[ef76686916d4](https://github.com/llvm/llvm-project/commit/ef76686916d4)

PiperOrigin-RevId: 328404846

google/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree