[Simplify redisplay-x/separate_textual_runs] Fix union build, shut up gcc

[Aidan Kehoe]

 Ar an t-aonú lá is triochad de mí Márta, scríobh Stephen J. Turnbull: 

 > Olivier Galibert writes:
 > 
 >  > The only part I'm really doubtful about is the ucs->byte split in the
 >  > -xft+mule translate_to_ics2 case.  I don't even know how to have the
 >  > code pass through there.
 > 
 > I think Aidan is the expert on that; I think that stuff is from his
 > JIT charsets work.  I took a hack at explaining it in my second post
 > (with the header comments, especially for -xft+mule), but I'd want
 > Aidan's review on that.

Evaluate this in *scratch* with Mule and server-side core fonts and the code
should pass through there on the next redisplay:

(mapc
 (lambda (code) (insert (format "%c " (decode-char 'ucs code))))
 (loop
   for i from 0 to #x10000
   with just-in-time-list = nil
   until (eq 20 (length just-in-time-list))
   finally return just-in-time-list
   do
   (when (and (decode-char 'ucs i)
	      (eq 'jit-ucs-charset-0 (char-charset (decode-char 'ucs i))))
     (push i just-in-time-list))))

If it doesn’t, check what 

(face-font-instance 'default nil 'jit-ucs-charset-0) 

returns; it should be an XLFD ending in -iso10646-1, and when you examine the
font using xfd(1), it should have a decent repertoire of characters (a
thousand, at least.) 

-- 
On the quay of the little Black Sea port, where the rescued pair came once
more into contact with civilization, Dobrinton was bitten by a dog which was
assumed to be mad, though it may only have been indiscriminating. (Saki)