Implements hook_node_predelete().
function menu_node_predelete(EntityInterface $node) {
  // Delete all menu module links that point to this node.
  $query = Drupal::entityQuery('menu_link')
    ->condition('link_path', 'node/' . $node->nid)
    ->condition('module', 'menu');
  $result = $query
    ->execute();
  if (!empty($result)) {
    menu_link_delete_multiple($result);
  }
}