Clean up another pre-ANSI-C-ism in regex code: get rid of pcolor typedef.

pcolor was used to represent function arguments that are nominally of
type color, but when using a pre-ANSI C compiler would be passed as the
promoted integer type.  We really don't need that anymore.

src/include/regex/regguts.h

@@ -149,7 +149,6 @@
  * which are of much more manageable number.
  */
 typedef short color;			/* colors of characters */
-typedef int pcolor;				/* what color promotes to */
 
 #define MAX_COLOR	32767		/* max color (must fit in 'color' datatype) */
 #define COLORLESS	(-1)		/* impossible color */