message: Add logging to notify users that with automatic outside compilation,
  uncompilable ops will be placed on CPU.
diff: @@ -1154,8 +1154,13 @@ def split_compile_and_replicate(computation,
  }
  metadata_kwargs["num_cores_per_replica"] = (
  device_assignment.num_cores_per_replica)
  +
  # This entry is used for enabling automatic outside compilation.
  metadata_kwargs["allow_soft_placement"] = config.get_soft_device_placement()
  + if config.get_soft_device_placement():
  + logging.info("Automatic outside compilation is enabled. "
  + "Ops without XLA kernels will be automatically "
  + "placed on CPU.")
  if ((not isinstance(inputs, list)) or
  any(not isinstance(inp, (list, tuple)) for inp in inputs)):
  