[v4] Right aligned dropdown in nav causes horizontal overflow

Created by: kedarv

This issue occurs on all desktop platforms. When you have a right aligned dropdown in the navigation bar, it overflows off the page creating a horizontal scroll and misplaced dropdown.

Demo v4 alpha 6: http://jsbin.com/sozuva/1 Demo v3 (desired behavior): http://jsbin.com/jorobic/1

I'm not sure if this issue is related to #22636 (closed)