message: Integrate LLVM at llvm/llvm-project@6699029b67bf
  Updates LLVM usage to match
  [6699029b67bf](https://github.com/llvm/llvm-project/commit/6699029b67bf)
diff: @@ -685,8 +685,8 @@ def tf_repositories(path_prefix = "", tf_repo_name = ""):
  )
  # Check out LLVM and MLIR from llvm-project.
  - LLVM_COMMIT = "39db5753f993abcc4289dd165e8297a4e28f4b0a"
  - LLVM_SHA256 = "d9d531b4867b39fa2da044598308f6d99458996d55eae0045843305876a4d424"
  + LLVM_COMMIT = "6699029b67bf0f5389896f9f929a344b64cfd9c7"
  + LLVM_SHA256 = "87a57030be20c4f42cd63499ebbf06013c80fa23186e199253b92512d1f1a054"
  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),
  