bug#14841: Frames created invisible have their visibility parameter set to t

[Eli Zaretskii]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Sat, 20 Jul 2013 16:54:05 +0200
> Cc: 14841@debbugs.gnu.org
> 
> (1) M-: (progn (setq *f* (make-frame '((visibility . X))))
> (frame-visible-p *f*)) <RET>
> (2) M-: (frame-visible-p *f*) <RET>
> 
>  X      (1)   (2)
> ------ ----- ------
>  t       t     t
>  nil    nil    t  <<<<<<<<< this is now nil
>  icon   nil   icon
> 
> I think both the (1) and (2) columns show bugs.

The last one seems like am artifact of how we implement iconified
frames on Windows.  I have no idea how to improve/fix that.