Roles: map add_users cap to promote_users and remove it.

"Never used, will be removed." - The Ghost of 3.5 Nacin

Props Craig Ralston, renoirb.
Fixes #16719.


git-svn-id: https://develop.svn.wordpress.org/trunk@35507 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/capabilities-functions.php

@@ -34,6 +34,7 @@ function map_meta_cap( $cap, $user_id ) {
 		$caps[] = 'remove_users';
 		break;
 	case 'promote_user':
+	case 'add_users':
 		$caps[] = 'promote_users';
 		break;
 	case 'edit_user':