Posts, Post Types: Introduce edit_post_{$post->post_type} hook.

The hook fires before the general `edit_post` hook and has the same parameters.

It also complements the `save_post_{$post->post_type}` hook added in [25050].

Props Mte90, garrett-eclipse.
Fixes #34706.

git-svn-id: https://develop.svn.wordpress.org/trunk@43535 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/comment.php

@@ -2471,6 +2471,10 @@ function wp_update_comment_count_now( $post_id ) {
 	 * @param int $old     The old comment count.
 	 */
 	do_action( 'wp_update_comment_count', $post_id, $new, $old );
+
+	/** This action is documented in wp-includes/post.php */
+	do_action( "edit_post_{$post->post_type}", $post_id, $post );
+
 	/** This action is documented in wp-includes/post.php */
 	do_action( 'edit_post', $post_id, $post );