bug#65051: internal_equal manipulates symbols with position without checking symbols-with-pos-enabled.

[Eli Zaretskii]

> Date: Sat, 5 Aug 2023 13:04:07 +0000
> Cc: 65051@debbugs.gnu.org, monnier@iro.umontreal.ca, acm@muc.de
> From: Alan Mackenzie <acm@muc.de>
> 
> > > No, only the bare symbol is in the obarray.  The symbol with position
> > > itself is a pseudovector, with contents (i) a bare symbol (a Lisp_Object
> > > "pointing at" the obarray) and (ii) the unsigned integer position.
> 
> > Please document this factoid in the ELisp manual, I think it's very
> > important, and having it undocumented is a Bad Thing.
> 
> DONE.  The change is near the top of the following patch, amended from
> the previous version.

LGTM, thanks.