bug#47067: 28.0.50; [feature/native-comp] Crash while scrolling through dispnew.c

[Eli Zaretskii]

> From: Andrea Corallo <akrl@sdf.org>
> Cc: pipcet@gmail.com, 47067@debbugs.gnu.org
> Date: Mon, 15 Mar 2021 20:17:18 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > I still see some strange phenomena with backtraces under GDB, which
> > tell me we sometimes clobber saved registers or something.  How else
> > to explain that one backtrace may be truncated after 20 frames, while
> > the next backtrace shows all the frames back to 'main'?
> >
> > What could explain this? another snafu with setjmp?
> 
> Dunno, but the only place where we emit setjmps is the one now fixed.

Fair enough.  I asked the GDB folks to help me analyze this.