Docs: Add documentation for the `$parent` parameter of `get_admin_page_parent()`.

Props subrataemfluence.
Fixes #45849.
Built from https://develop.svn.wordpress.org/trunk@47546


git-svn-id: http://core.svn.wordpress.org/trunk@47321 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/plugin.php

@@ -1821,6 +1821,8 @@ function menu_page_url( $menu_slug, $echo = true ) {
  * @global array  $_wp_menu_nopriv
  * @global array  $_wp_submenu_nopriv
  *
+ * @param string $parent The slug name for the parent menu (or the file name of a standard
+ *                       WordPress admin page). Default empty string.
  * @return string The parent file of the current admin page.
  */
 function get_admin_page_parent( $parent = '' ) {

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5-alpha-47545';
+$wp_version = '5.5-alpha-47546';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.