bug#58671: gui-backend-set-selection causing segfault on Debian 12

[Eli Zaretskii]

> From: Geoffrey Ferrari <geoffrey.ferrari@oriel.oxon.org>
> Date: Thu, 20 Oct 2022 22:57:41 +0100
> 
> To reproduce:
> Highlight some text and run kill-ring-save which ultimately calls 
> gui-backend-set-selection.
> 
> Kind regards,
> 
> Geoff
> 
> In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
>  3.24.34, cairo version 1.16.0) of 2022-10-17, unofficial
>  emacs-snapshot build: http://emacs.secretsauce.net built on
>  lilbastard
> Windowing system distributor 'The X.Org Foundation', version 11.0.12101004
> System Description: Debian GNU/Linux bookworm/sid

It is unclear from which commit of the Emacs Git repository was this
built.  AFAIR, there were some problems in this area fixed lately on
master, so perhaps try with the current master branch.