Add @static* annotations where they are missing.

Initialize all static vars that are not, most to `null`.

See #32444.


git-svn-id: https://develop.svn.wordpress.org/trunk@32650 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/screen.php

@@ -11,6 +11,8 @@
  *
  * @since 2.7.0
  *
+ * @staticvar array $column_headers
+ *
  * @param string|WP_Screen $screen The screen you want the headers for
  * @return array Containing the headers in the format id => UI String
  */
@@ -327,6 +329,11 @@ final class WP_Screen {
 
 	/**
 	 * Stores old string-based help.
+	 *
+	 * @static
+	 * @access private
+	 *
+	 * @var array
 	 */
 	private static $_old_compat_help = array();
 
@@ -343,8 +350,11 @@ final class WP_Screen {
 	 * The screen object registry.
 	 *
 	 * @since 3.3.0
-	 * @var array
+	 *
+	 * @static
 	 * @access private
+	 *
+	 * @var array
 	 */
 	private static $_registry = array();
 
@@ -372,6 +382,8 @@ final class WP_Screen {
 	 * @since 3.3.0
 	 * @access public
 	 *
+	 * @static
+	 *
 	 * @global string $hook_suffix
 	 *
 	 * @param string|WP_Screen $hook_name Optional. The hook name (also known as the hook suffix) used to determine the screen.
@@ -588,6 +600,8 @@ final class WP_Screen {
 	 *
 	 * @since 3.3.0
 	 *
+	 * @static
+	 *
 	 * @param WP_Screen $screen A screen object.
 	 * @param string $help Help text.
 	 */
@@ -974,7 +988,7 @@ final class WP_Screen {
 	/**
 	 *
 	 * @global array $wp_meta_boxes
-	 * 
+	 *
 	 * @return bool
 	 */
 	public function show_screen_options() {