message: Use the known fixed size of the tensor array instead of the dynamic one
  For compatibility with XLA:  The tensorarray.size() operator produces
  graphs which are not caompatible with XLA.  The size of the tensor
  array is known explicitly, so by using that size we can avoid the
  incompatibility.
diff: @@ -810,7 +810,8 @@ def _dynamic_rnn_loop(cell,
  # Unpack final output if not using output tuples.
  if in_graph_mode:
  - final_outputs = tuple(ta.stack() for ta in output_final_ta)
  + final_outputs = tuple(
  + ta.gather(range(time_steps)) for ta in output_final_ta)
  # Restore some shape information
  for output, output_size in zip(final_outputs, flat_output_size):
  shape = _concat(
  