wp_cache_post_edit() on menu items calls after Save of menu, is that right?

Getting this PHP stacktrace (I have xdebug installed) after hitting Save on a menu, after removing some menu items from it.

```
( ! ) Fatal error: Maximum execution time of 30 seconds exceeded in /var/www/html/myuser/domains/mysite.it/wp-includes/load.php on line 939
Call Stack
# Time Memory Function Location
1 0.0011 574904 {main}( ) .../nav-menus.php:0
2 1.5977 26711952 wp_nav_menu_update_menu_items( ) .../nav-menus.php:368
3 77.6695 26811416 wp_delete_post( ) .../nav-menu.php:1046
4 77.7827 26817568 do_action( ) .../post.php:2414
5 77.7827 26818984 call_user_func_array:{/var/www/html/myuser/domains/mysite.it/wp-includes/plugin.php:524} ( ) .../plugin.php:524
6 77.7827 26819016 wp_cache_post_edit( ) .../plugin.php:524
7 77.7828 26819336 wp_cache_post_change( ) .../wp-cache-phase2.php:1117
8 97.3421 26824528 get_permalink( ) .../wp-cache-phase2.php:1248
9 97.3422 26826768 get_option( ) .../link-template.php:150
10 97.3422 26826952 wp_load_alloptions( ) .../option.php:78
11 97.3422 26826952 wp_installing( ) .../option.php:177
```

So I wondered if does it make sense to call `wp_cache_post_edit()` on a post of type 'nav_menu_item'.

note: line numbers of wp-cache-phase2.php may not correspond to 1.4.9 coz of some mods and comments I made, the lines are:

what is said to be 1117:
```php
wp_cache_post_change( $post_id ); // from inside function wp_cache_post_edit($post_id) {
```

what is said to be 1248:
```php
$permalink = trailingslashit( str_replace( get_option( 'home' ), '', get_permalink( $post_id ) ) );
```

I didn't inspected the code further, I don't know exactly why my installation went into an axecution timeout, it never does. And I don't inspected further how WPSC handles post of 'nav_menu_item' type.

FYI, the menu items I removed were two static external links like bla1.org and bla2.org, so they shouldn't impact on local cache either way.

Reproduce saving a WordPress menu after removing external-link items, then trace nav-menus.php:368 through wp-includes/nav-menu.php:1046 and wp_cache_post_edit() in wp-cache-phase2.php. Inspect the calls to wp_cache_post_change(), get_permalink(), and wp_load_alloptions() around the reported lines; done means the timeout path and expected handling of nav_menu_item are established.

Written by the indexing model from the issue text.