bug#27178: 26.0.50; libxml-parse-*-region functions ignore discard-comments argument

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: npostavs@users.sourceforge.net,  27178@debbugs.gnu.org,  eefacm@gmail.com
> Date: Sat, 14 Apr 2018 15:54:05 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> On the other hand, we could deprecate that option (since it's rather
> >> nonsensical the way it is now), and just provide a Lisp convenience
> >> function to delete the comments if you don't want comments?  I think
> >> that sounds cleaner and much easier to implement.
> >
> > That is also fine with me, thanks.
> 
> Hm...  do we have a mechanism to mark parameters as obsolete

I don't believe so, but maybe others will have me corrected.

> or should I just mention it in the doc string?

If that's the only way, yes, please.