message: Add __getstate__ and __setstate__ to name_scope_v2 s.t. it can be pickled now that it has __slots__.
diff: @@ -6672,6 +6672,13 @@ class name_scope_v2(object):
  self._exit_fns.pop()(type_arg, value_arg, traceback_arg)
  return False # False values do not suppress exceptions
  + def __getstate__(self):
  + return self._name, self._exit_fns
  +
  + def __setstate__(self, state):
  + self._name = state[0]
  + self._exit_fns = state[1]
  +
  def strip_name_scope(name, export_scope):
  """Removes name scope from a name.
  