patch: #defines

This is a fairly trivial code change but should have been done long ago...

include/hack.h

@@ -306,6 +306,10 @@ NEARDATA extern coord bhitpos;	/* place where throw or zap hits or stops */
 #define RANDOM_TIN  (-2)
 #define HEALTHY_TIN (-3)
 
+/* Some misc definitions */
+#define POTION_OCCUPANT_CHANCE(n) (13 + 2*(n))
+#define WAND_BACKFIRE_CHANCE 100
+
 /* Flags to control menus */
 #define MENUTYPELEN sizeof("traditional ")
 #define MENU_TRADITIONAL 0