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/upgrade.php

@@ -35,6 +35,12 @@ if ( 'upgrade_db' === $step ) {
 	die( '0' );
 }
 
+/**
+ * @global string $wp_version
+ * @global string $required_php_version
+ * @global string $required_mysql_version
+ * @global wpdb   $wpdb
+ */
 global $wp_version, $required_php_version, $required_mysql_version;
 
 $step = (int) $step;