menu_rebuild slow down performance for site that using hundred or thousand fields

My site is using 261 content types with 1750 fields. Whenever I'm running drush cc all or drush updb, the performance was very poor and it was often didn't finish, and worse, it made the site could not be accessed.

Eventually I realized that while running clear cache or update db, it called menu_rebuild to rebuild the menu. CCK, whenever there's a new field, it will add a new menu dynamically. At least there are 2 menu added for each field: configure and delete.

To avoid thousand menu being rendered for my production site (I don't need to configure or delete fields in my production site), I create the patch to give an option whether the field menu will be rendered or not. Here is the patch.