bug#49558: fill paragraph in texinfo-mode fails with @

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Stefan Monnier <monnier@iro.umontreal.ca>,  lisa-asket@perso.be,
>   49558@debbugs.gnu.org
> Date: Wed, 14 Jul 2021 15:00:48 +0200
> 
> > @node Foo Bar Baz Quux Very Long Node Name
> >
> > @subsection This is a very long subsection name
> >
> > @cindex a very long index entry that could wrap
> >
> > @defun my-func with many different arguments that could wrap
> >
> > @end multitable
> 
> The problem is that all of that is currently a single paragraph -- and I
> don't think that's something we want?  (Try saying
> `M-: (forward-paragraph)' at the start.)

What exactly do we not want in the result of forward-paragraph in
these cases?  I'm probably missing something.