Docs: Further corrections and promotions for docblocks relating to object types.

See #50768


git-svn-id: https://develop.svn.wordpress.org/trunk@49197 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/user.php

@@ -1526,7 +1526,7 @@ function sanitize_user_field( $field, $value, $user_id, $context ) {
  *
  * @since 3.0.0
  *
- * @param WP_User $user User object to be cached
+ * @param object|WP_User $user User object or database row to be cached
  * @return bool|null Returns false on failure.
  */
 function update_user_caches( $user ) {