bug#31315: wrong font encoding for fallback font

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Werner LEMBERG <wl@gnu.org>,  handa@gnu.org,  31315@debbugs.gnu.org
> Date: Tue, 01 May 2018 19:42:16 +0200
> 
> On Mai 01 2018, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > Andreas, given that '("gb18030" (gb18030 . unicode))' appears to work,
> > do you see any potential problems with using it, instead of
> > gb18030-2-byte?
> 
> I leave that question to those who are more knowledgeable of the X font
> interface.

I invite those people to chime in.  Meanwhile, I pushed that change to
the master branch, and I'm boldly marking this bug "done".

Thanks.