user_user_role_delete

user_user_role_delete(RoleInterface $role)

function user_user_role_delete(RoleInterface $role) {
  // Delete role references for all users.
  $user_storage = \Drupal::entityManager()->getStorage('user');
  $user_storage->deleteRoleReferences(array($role->id()));

  // Ignore the authenticated and anonymous roles or the role is being synced.
  if (in_array($role->id(), array(RoleInterface::AUTHENTICATED_ID, RoleInterface::ANONYMOUS_ID)) || $role->isSyncing()) {
    return;
  }

  $actions = Action::loadMultiple([
    'user_add_role_action.' . $role->id(),
    'user_remove_role_action.' . $role->id(),
  ]);
  foreach ($actions as $action) {
    $action->delete();
  }
}