message: Set `_is_compiled` attribute for Keras custom compile for predict.
diff: @@ -671,6 +671,12 @@ def _prepare_feed_values(model, inputs, targets, sample_weights, mode):
  def _custom_compile_for_predict(model):
  """Custom compile for TPU predict mode."""
  + if not model.built:
  + # Model is not compilable because it does not know its number of inputs
  + # and outputs, nor their shapes and names. We will compile after the first
  + # time the model gets called on training data.
  + return
  + model._is_compiled = True
  model.total_loss = None
  model._fit_function = None
  model._eval_function = None
  