message: Fix exit handler memory error when it use refcounted value.
diff: @@ -255,6 +255,8 @@ static int coro_exit_handler(zend_execute_data *execute_data)
  {
  exit_status = Z_REFVAL_P(exit_status);
  }
  + ZVAL_DUP(&_exit_status, exit_status);
  + exit_status = &_exit_status;
  }
  else
  {
  