Add @global annotations for wp-admin/*.

See #32444.


git-svn-id: https://develop.svn.wordpress.org/trunk@32642 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/network/upgrade.php

@@ -48,6 +48,9 @@ switch ( $action ) {
 		$n = ( isset($_GET['n']) ) ? intval($_GET['n']) : 0;
 
 		if ( $n < 5 ) {
+			/**
+			 * @global string $wp_db_version
+			 */
 			global $wp_db_version;
 			update_site_option( 'wpmu_upgrade_site', $wp_db_version );
 		}