bug#36649: 27.0.50; pure space and pdumper

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Eli Zaretskii <eliz@gnu.org>,  pipcet@gmail.com,  eggert@cs.ucla.edu,
>   rpluim@gmail.com,  schwab@linux-m68k.org,  stefan@marxist.se,
>   36649@debbugs.gnu.org,  akrl@sdf.org
> Date: Wed, 12 May 2021 19:11:21 +0200
> 
> Stefan Monnier <monnier@iro.umontreal.ca> writes:
> 
> > I thought the question was not directly relevant because removal of the
> > pure space does not imply removing unexec.
> 
> It just makes unexec Emacs a little less efficient?  In which case I say
> we should just ignore the issue and apply the patch.

Keeping unexec doesn't mean breaking it .  If we believe someone might
need that configuration, then we should give them a full-fledged
Emacs, not a crippled one.

The patch can easily be tweaked to make the changes conditioned by
HAVE_PDUMPER, so I believe there's no need to argue about this nit:
let's simply remove purespace from the pdumper builds, and leave it
alone in the unexec builds.