Application menus at screen border

[topolinik]

I've seen this in haiku 32 bit beta4 hrev 56578+70 run into a virtualbox VM.

When clicking on an application menu bar and the main app window lies on the very right border of the screen, the last reachable menu entry shows its menu left-moved in order to make it entirely visible. This is into 'haiku_menu_right_border_perfect.png'

This behaviour is not applied to menu entries placed at the left desktop border, where the last 'clickable' menu entry shows the menu aligned as usual, and the result is a partially hidden menu. This is into 'haiku_menu_left_border_wrong.png'

I think this is only a matter of replicating a check the code already does for the right border, but on the left border.