bug#51758: 27.2; Backtrace put in home dir, not current dir

[Eli Zaretskii]

> From: Scott Otterson <scotto@sharpleaf.org>
> Date: Tue, 20 Sep 2022 10:02:00 -0700
> Cc: Lars Ingebrigtsen <larsi@gnus.org>, 51758@debbugs.gnu.org
> 
> Maybe the solution is to put it in some totally unambiguous place:
> 
>   ~/.emacs.crashdump (or whatever)
> 
>  and then change the docs to match.

No, doing anything non-trivial when Emacs is crashing runs the risk of
jeopardizing the backtrace production.