Docs: Document some globals in wp-includes/widgets.php.

Follow-up to [41555], [50995].

Props upadalavipul.
See #60021.

git-svn-id: https://develop.svn.wordpress.org/trunk@57216 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/widgets.php

@@ -1544,6 +1544,8 @@ function wp_map_sidebars_widgets( $existing_sidebars_widgets ) {
  *
  * @since 4.9.0
  *
+ * @global array $wp_registered_widgets
+ *
  * @param array $sidebars_widgets   List of sidebars and their widget instance IDs.
  * @param array $allowed_widget_ids Optional. List of widget IDs to compare against. Default: Registered widgets.
  * @return array Sidebars with allowed widgets.
@@ -1968,6 +1970,9 @@ function wp_assign_widget_to_sidebar( $widget_id, $sidebar_id ) {
  *
  * @since 5.8.0
  *
+ * @global array $wp_registered_widgets
+ * @global array $wp_registered_sidebars
+ *
  * @param string $widget_id Widget ID.
  * @param string $sidebar_id Sidebar ID.
  * @return string
@@ -2034,6 +2039,8 @@ function wp_render_widget( $widget_id, $sidebar_id ) {
  *
  * @since 5.8.0
  *
+ * @global array $wp_registered_widget_controls
+ *
  * @param string $id Widget ID.
  * @return string|null
  */