[MIRROR] Ports chasm exceptions to typecaches (#2777)

* Ports chasm exceptions to typecaches (#30717)

* Ports chasm exceptions to typecaches

* Ports chasm exceptions to typecaches

code/game/turfs/simulated/chasm.dm

@@ -11,6 +11,7 @@
 	canSmoothWith = list(/turf/open/floor/fakepit, /turf/open/chasm)
 	density = TRUE //This will prevent hostile mobs from pathing into chasms, while the canpass override will still let it function like an open turf
 	var/static/list/falling_atoms = list() //Atoms currently falling into the chasm
+	var/static/list/forbidden_types = typecacheof(list(/obj/effect/portal, /obj/singularity, /obj/structure/stone_tile, /obj/item/projectile, /obj/effect/abstract, /obj/effect/temp_visual))
 	var/drop_x = 1
 	var/drop_y = 1
 	var/drop_z = 1
@@ -88,12 +89,7 @@
 		return FALSE
 	if(!isliving(AM) && !isobj(AM))
 		return FALSE
-	if(istype(AM, /obj/singularity) || istype(AM, /obj/item/projectile) || AM.throwing)
-		return FALSE
-	if(istype(AM, /obj/effect/portal))
-		//Portals aren't affected by gravity. Probably.
-		return FALSE
-	if(istype(AM, /obj/structure/stone_tile))
+	if(is_type_in_typecache(AM, forbidden_types) || AM.throwing)
 		return FALSE
 	//Flies right over the chasm
 	if(isliving(AM))
@@ -110,6 +106,7 @@
 			return FALSE
 	return TRUE
 
+
 /turf/open/chasm/proc/drop(atom/movable/AM)
 	//Make sure the item is still there after our sleep
 	if(!AM || QDELETED(AM))