Ticket #58887: 58887.1.diff

src/wp-includes/admin-bar.php

@@ -940 +940 @@
                 $actions['post-new.php?post_type=page'] = array( $cpts['page']->labels->name_admin_bar, 'new-page' );
         }
 
-        unset( $cpts['post'], $cpts['page'], $cpts['attachment'] );
+        if ( isset( $cpts['wp_block'] ) && true === use_block_editor_for_post_type( $cpts['wp_block']->name ) && current_user_can( $cpts['wp_block']->cap->create_posts ) ) {
+                $actions['post-new.php?post_type=wp_block'] = array( $cpts['wp_block']->labels->name_admin_bar, 'new-wp_block' );
+        }
+
+        unset( $cpts['post'], $cpts['page'], $cpts['attachment'], $cpts['wp_block'] );
 
         // Add any additional custom post types.
         foreach ( $cpts as $cpt ) {

src/wp-includes/post.php

@@ -307 +307 @@
                         '_builtin'              => true, /* internal use only. don't use this when registering your own post type. */
                         'show_ui'               => true,
                         'show_in_menu'          => false,
+                        'show_in_admin_bar'     => true,
                         'rewrite'               => false,
                         'show_in_rest'          => true,
                         'rest_base'             => 'blocks',