Include `post__in` as a value available to the `orderby` parameter in the docs for `WP_Query::parse_query()`.

See #32246

Built from https://develop.svn.wordpress.org/trunk@34836


git-svn-id: http://core.svn.wordpress.org/trunk@34801 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/query.php

@@ -1534,8 +1534,8 @@ class WP_Query {
 	 *                                                 specific `$meta_query` clause, use that clause's array key.
 	 *                                                 Default 'date'. Accepts 'none', 'name', 'author', 'date',
 	 *                                                 'title', 'modified', 'menu_order', 'parent', 'ID', 'rand',
-	 *                                                 'comment_count', 'meta_value', 'meta_value_num', and the
-	 *                                                 array keys of `$meta_query`.
+	 *                                                 'comment_count', 'meta_value', 'meta_value_num', 'post__in',
+	 *                                                 and the array keys of `$meta_query`.
 	 *     @type int          $p                       Post ID.
 	 *     @type int          $page                    Show the number of posts that would show up on page X of a
 	 *                                                 static front page.

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34834';
+$wp_version = '4.4-alpha-34836';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.