message: Change global step to int64.
diff: @@ -68,12 +68,11 @@ def _create_global_step(graph):
  return variable_scope.get_variable(
  ops.GraphKeys.GLOBAL_STEP,
  shape=[],
  - dtype=dtypes.int32,
  + dtype=dtypes.int64,
  initializer=init_ops.zeros_initializer(),
  trainable=False,
  use_resource=True,
  - collections=[ops.GraphKeys.GLOBAL_VARIABLES,
  - ops.GraphKeys.GLOBAL_STEP])
  + collections=[ops.GraphKeys.GLOBAL_VARIABLES, ops.GraphKeys.GLOBAL_STEP])
  def _sync_variables_ops():
  