message: Add a comment in tf_upgrade_v2.py to indicate order of arguments in
  self.function_reorders should match old order as opposed to new order.
diff: @@ -66,6 +66,8 @@ class TFAPIChangeSpec(ast_edits.APIChangeSpec):
  # Functions that were reordered should be changed to the new keyword args
  # for safety, if positional arguments are used. If you have reversed the
  # positional arguments yourself, this could do the wrong thing.
  + # IMPORTANT: order here should correspond to OLD argument order.
  + # We just prepend "arg_name=" to all arguments in function calls.
  self.function_reorders = {
  "tf.argmax": ["input", "axis", "output_type", "name"],
  "tf.argmin": ["input", "axis", "output_type", "name"],
  