bug#50339: master creashed in compact_small_strings

[Eli Zaretskii]

> From: Richard Stallman <rms@gnu.org>
> Cc: 50339@debbugs.gnu.org
> Date: Sun, 05 Sep 2021 23:08:11 -0400
> 
>   > Look like bogus values.
> 
>   > Very strange.
> 
>   > Does anyone have any idea how this could happen?
> 
> It could be a random hardware failure.
> Such things have happened.

Yes, that's one thing that crossed my mind.  Did you have hardware
problems on this machine in the past?