Make SINKS unconditional.

src/hack.c

@@ -10,9 +10,7 @@
 STATIC_DCL void NDECL(maybe_wail);
 STATIC_DCL int NDECL(moverock);
 STATIC_DCL int FDECL(still_chewing,(XCHAR_P,XCHAR_P));
-#ifdef SINKS
 STATIC_DCL void NDECL(dosinkfall);
-#endif
 STATIC_DCL boolean FDECL(findtravelpath, (BOOLEAN_P));
 STATIC_DCL boolean FDECL(trapmove, (int,int,struct trap *));
 STATIC_DCL void NDECL(switch_terrain);
@@ -468,7 +466,6 @@ register xchar ox, oy;
 	newsym(ox, oy);
 }
 
-#ifdef SINKS
 static NEARDATA const char fell_on_sink[] = "fell onto a sink";
 
 STATIC_OVL void
@@ -549,7 +546,6 @@ dosinkfall()
 	   through float_down(), but make sure BFlying is up to date */
 	float_vs_flight();
 }
-#endif
 
 boolean
 may_dig(x,y)
@@ -1767,10 +1763,8 @@ boolean pick;
 	if (pooleffects(TRUE)) goto spotdone;
 
 	check_special_room(FALSE);
-#ifdef SINKS
 	if(IS_SINK(levl[u.ux][u.uy].typ) && Levitation)
 		dosinkfall();
-#endif
 	if (!in_steed_dismounting) { /* if dismounting, we'll check again later */
 		boolean pit;