bug#36649: 27.0.50; pure space and pdumper

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Date: Thu, 04 Mar 2021 15:56:10 +0100
> Cc: eggert@cs.ucla.edu, Andreas Schwab <schwab@linux-m68k.org>,
>  Stefan Kangas <stefankangas@gmail.com>, 36649@debbugs.gnu.org, 
> larsi@gnus.org,
>  Andrea Corallo <akrl@sdf.org>
> 
> I think Emacs already assumes Qnil == 0, since there are places that
> use ! to check for Qnil rather than using NILP.

Those are bugs that need to be fixed.  Fast.