bug#50268: 28.0.50; Assertion warning during native compilation

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Stefan Monnier <monnier@iro.umontreal.ca>,  Eli Zaretskii
>  <eliz@gnu.org>,  Noam Postavsky <npostavs@gmail.com>,
>   50268@debbugs.gnu.org
> Date: Thu, 23 Sep 2021 23:03:04 +0200
> 
> Mattias Engdegård <mattiase@acm.org> writes:
> 
> > Allowing &rest without a variable name following turned out not to be
> > very useful, and it never worked properly.  Disallow it.
> 
> Makes sense to me.  Since it's that non-invasive, I think it'd be fine
> to push to Emacs 28.  Perhaps Eli has a different opinion, though.

Let's do it now.

Thanks.