Privacy: Correct type of WP_User_Request::$user_id from int to string/numeric-string.

Also adds `numeric-string` as richer PHPStan type to `WP_Post::$post_author` and `WP_Post::$comment_count`.

Developed in WordPress#12018.
Follow-up to r25086, r43011.

Props masteradhoc, desrosj, garrett-eclipse, johnbillion, westonruter, apermo, SergeyBiryukov, TZ-Media, andizer, javorszky.
See #22324, #25092, #43443, #43985, #64898.
Fixes #44723.


git-svn-id: https://develop.svn.wordpress.org/trunk@62437 602fd350-edb4-49c9-b593-d223f7449a82

Author: westonruter

src/wp-includes/class-wp-post.php

@@ -36,6 +36,7 @@ final class WP_Post {
 	 *
 	 * @since 3.5.0
 	 * @var string
+	 * @phpstan-var numeric-string
 	 */
 	public $post_author = '0';
 
@@ -206,6 +207,7 @@ final class WP_Post {
 	 *
 	 * @since 3.5.0
 	 * @var string
+	 * @phpstan-var numeric-string
 	 */
 	public $comment_count = '0';
 

src/wp-includes/class-wp-user-request.php

@@ -20,9 +20,10 @@ final class WP_User_Request {
 	 * User ID.
 	 *
 	 * @since 4.9.6
-	 * @var int
+	 * @var string
+	 * @phpstan-var numeric-string
 	 */
-	public $user_id = 0;
+	public $user_id = '0';
 
 	/**
 	 * User email.