bug#57937: 29.0.50; Improve doc of (interactive current-prefix-arg ...)

[Eli Zaretskii]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Mon, 19 Sep 2022 15:35:12 -0400
> Cc: 57937@debbugs.gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > There is already such a pointer there:
> >
> >    There are three possibilities for the argument ARG-DESCRIPTOR:
> >
> >    • It may be omitted or ‘nil’; ...
> >    • It may be a string; ...
> 
> I was thinking of this item:
> 
>    • It may be a Lisp expression that is not a string; ...
> 
> Here, I'd like to see an example like:
> 
>           (interactive current-prefix-arg)
> 
> and a brief pointer to `(elisp) Prefix Command Arguments'.

That comes _after_ the above-mention place, which already points to
that node, so what would be the point and the importance of repeating
the reference?  Using current-prefix-arg in a Lisp expression is not
different from using any other Lisp variable.