bug#52461: spontaneous crash with portable dumper

[Eli Zaretskii]

> Date: Wed, 15 Dec 2021 12:04:31 +0900
> From: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
> Cc: pipcet@gmail.com,
>       52461@debbugs.gnu.org
> 
> On Tue, 14 Dec 2021 22:20:30 +0900,
> Eli Zaretskii wrote:
> > 
> > Thanks.  I think I prefer the second variant.
> > 
> > Do you think we need more testing of this, since the problem was
> > intermittent?
> 
> I don't think so.  The members of struct charset other than
> code_space_mask is non-pointer values, so they do not involve any
> dereference.
> 
> Can I install it to the emacs-28 branch?

Yes, please.