bug#50268: 28.0.50; Assertion warning during native compilation

[Noam Postavsky]

Mattias Engdegård <mattiase@acm.org> writes:

> 21 sep. 2021 kl. 18.11 skrev Lars Ingebrigtsen <larsi@gnus.org>:
>
>> I did a quick grep through core and GNU ELPA, and I couldn't find any
>> instances of it being used, so I'd be fine with either solution (i.e.,
>> either fixing the bug or signalling an error).
>
> I know how to fix it but there's no really elegant way of doing it,
> and unless a convincing case can be made for permitting anonymous
> &rest, I'd favour disallowing it.
>
> Unless I'm mistaken it was Noam who added it
> (1d47d777ef24c0be9153b0a1c8ba21918fa1025a), so let's ask him.

It's been a while, but looking at Bug#29165, the reason I added it is
that it was supported in Emacs 25 and earlier.  Stefan M had some
justifications there for &optional without variables, but I think they
don't apply for &rest.