The #definition of COMBINED was done very badly: it was a piece of

platform-dependent code in puzzles.h (ick), which in turn depended
on the magic symbol MAC_OS_X being defined by mkfiles.pl itself
(yuck). Suddenly realised I can do much better simply by putting it
in an OS X makefile extras section in Recipe, and removing both
previous hacks. Much nicer.

[originally from svn r5191]

puzzles.h

@@ -199,14 +199,6 @@ struct game {
     int (*wants_statusbar)(void);
 };
 
-/*
- * Here we include the knowledge of which platforms are of which
- * type.
- */
-#ifdef MAC_OS_X   /* this must be defined in the OS X Makefile */
-#define COMBINED
-#endif
-
 /*
  * For one-game-at-a-time platforms, there's a single structure
  * like the above, under a fixed name. For all-at-once platforms,