message: Integrate LLVM at llvm/llvm-project@76b6cb515b2f
  Updates LLVM usage to match
  [76b6cb515b2f](https://github.com/llvm/llvm-project/commit/76b6cb515b2f)
diff: @@ -686,8 +686,8 @@ def tf_repositories(path_prefix = "", tf_repo_name = ""):
  )
  # Check out LLVM and MLIR from llvm-project.
  - LLVM_COMMIT = "a7b65741441556d295079fc4f2391d99fd1c1111"
  - LLVM_SHA256 = "7a08492e3190b8d9b804e2fc0ab06b13970ba52ef87317f21c357a9388a91563"
  + LLVM_COMMIT = "76b6cb515b2f385f8cdd3c41ecd31c78698f20b2"
  + LLVM_SHA256 = "711ce462f3c48bbc17395c160790f9221469c90f0b5a8419f5b758221fc5c1ef"
  LLVM_URLS = [
  "https://storage.googleapis.com/mirror.tensorflow.org/github.com/llvm/llvm-project/archive/{commit}.tar.gz".format(commit = LLVM_COMMIT),
  "https://github.com/llvm/llvm-project/archive/{commit}.tar.gz".format(commit = LLVM_COMMIT),
  