delete user link causes assign posts page to hang if a large number of users exist in db

[commentluv]

if a delete user link is clicked, the delete user page where you choose to attribute or delete their posts hangs if a large amount of users exist.

my site has approx 50,000 users and the user delete page does not load fully due to all 50,000 users having to be displayed in the dropdown box.

there should be a way to 'delete user and discard posts' to bypass this screen or only load a maximum number of users in the dropdown list or do not show the attribution page if the user has no posts

I should point out that this only hangs in Chrome , firefox is ok

#19867, #20769