message: enable llvm::AArch64CodeGen
  needed by mlir, e.g.,
  `//tensorflow/compiler/mlir/tools/kernel_gen/tf_to_kernel`
diff: @@ -798,9 +798,10 @@ def tf_google_mobile_srcs_only_runtime():
  return []
  def if_llvm_aarch64_available(then, otherwise = []):
  - # TODO(b/...): The TF XLA build fails when adding a dependency on
  - # @llvm/llvm-project/llvm:aarch64_target.
  - return otherwise
  + return select({
  + "//tensorflow:linux_aarch64": then,
  + "//conditions:default": otherwise,
  + })
  def if_llvm_system_z_available(then, otherwise = []):
  return select({
  