user32: Make all the recently added ShowWindow tests pass in Wine

[Tomas Carnecky]

Tomas Carnecky wrote:
> Minimizing: I started the game, minimized it and then the log starts:
> maximize it and minimize it.
> 

I'm sorry, this is the wrong description. ALT-TAB switches the active
window, like under Windows, it does not minimize!

Even without your patch I can see the slowdown when I 'Iconify' the
window (ALT + right mouse button brings up a context menu where I can
select such actions). However, I can make the game run normal again by
pressing ALT-TAB a few times.

tom