bug#58909: 29.0.50; [WIP PATCH] Deleting the last frame of an emacsclient doesn't ask to save

[Eli Zaretskii]

> Date: Tue, 1 Nov 2022 15:39:29 -0700
> From: Jim Porter <jporterbugs@gmail.com>
> Cc: 58909@debbugs.gnu.org
> 
> Attached is a (hopefully) safer version of my change to 'delete-frame'. 
> In this patch, a hook can only cancel frame deletion if FORCE is 
> non-nil. This way, if there were ever some bug with a hook, you (or some 
> code) can still force-delete the frame.

Sorry, but I still don't like this.  We currently call this hook via
safe_call because we don't want to let the hook prevent the deletion
of the frame.

I prefer to solve this in server.el, not in lower-level primitives.