bug#59794: 29.0.60; NSport segfaults when a fullscreen frame is being closed

[Eli Zaretskii]

> From: Kai Ma <justksqsf@gmail.com>
> Date: Fri, 02 Dec 2022 20:01:31 +0800
> 
> 
> Emacs segfaults when a fullscreen frame is being deleted.
> 
> Steps to reproduce on emacs -Q:
> 
> 1. Launch an emacs instance.  The default frame should be in the window
>    mode for now.
> 
> 2. C-x 5 2
> 
> 3. In the new frame, M-x toggle-frame-fullscreen.
> 
> 4. In the new frame, C-x 5 0 to delete the frame.
> 
> Emacs then segfaults.

It doesn't segfault on MS-Windows, so I guess this is NS-specific.