[A21.5] Fix non-MULE Xft build

[Stephen J. Turnbull]

APPROVE 21.5

Michael Sperber writes:

 > Stephen, could you review this?
 > 
 >  2006-11-18  Mike Sperber  <mike at xemacs.org>
 >  
 > 	* redisplay-x.c (separate_textual_runs): Don't try to call
 > 	ichar_to_unicode on non-MULE.

It looks to me like this is implied by the Xft font model (font
indicies are always Unicode).  That means that when using Xft, the
classical localization trick of using a non-Latin-1 unibyte font isn't
going to work no matter what.  So no harm done by this fix.

It might make more sense to

#if !defined (MULE) && defined (USE_XFT)
#define ichar_to_unicode(ch) (ch)
#endif

in some appropriate place, but I don't think it's worth the effort
since this function is only used in a couple of places anyway.

Aidan, what do you think?