[MIRROR] Gets rid of hasvar usage and moves up some vars (#11484)

Co-authored-by: Cameron Lennox <killer65311@gmail.com>

code/game/objects/structures/barricades.dm

@@ -45,9 +45,9 @@
 		return
 	else
 		switch(W.damtype)
-			if("fire")
+			if(BURN)
 				health -= W.force * 1
-			if("brute")
+			if(BRUTE)
 				health -= W.force * 0.75
 		if(material == (get_material_by_name(MAT_WOOD) || get_material_by_name(MAT_SIFWOOD)))
 			playsound(src, 'sound/effects/woodcutting.ogg', 100, 1)

code/game/objects/structures/ghost_pods/antagonist.dm

@@ -36,9 +36,9 @@
 /obj/structure/ghost_pod/automatic/xenomorph_egg/attackby(obj/item/W as obj, mob/user as mob)
 	user.setClickCooldown(user.get_attack_speed(W))
 	switch(W.damtype)
-		if("fire")
+		if(BURN)
 			health -= W.force * 1.25 //It really doesn't like fire
-		if("brute")
+		if(BRUTE)
 			health -= W.force * 0.75 //Bit hard to cut
 	playsound(src, 'sound/effects/attackblob.ogg', 50, 1)
 	healthcheck()
@@ -46,10 +46,10 @@
 	return
 
 /obj/structure/ghost_pod/automatic/xenomorph_egg/bullet_act(var/obj/item/projectile/Proj)
-	switch(damtype)
-		if("fire")
+	switch(Proj.damtype)
+		if(BURN)
 			health -= Proj.damage * 1.5 //It burns!
-		if("brute")
+		if(BRUTE)
 			health -= Proj.damage //It hurts a bit more then a sharp stick
 	healthcheck()
 	..()

code/game/objects/structures/grille.dm

@@ -155,9 +155,9 @@
 		user.do_attack_animation(src)
 		playsound(src, 'sound/effects/grillehit.ogg', 80, 1)
 		switch(W.damtype)
-			if("fire")
+			if(BURN)
 				health -= W.force
-			if("brute")
+			if(BRUTE)
 				health -= W.force * 0.1
 	healthcheck()
 	..()

code/game/objects/structures/low_wall.dm

@@ -263,8 +263,8 @@
 	if(ismob(AM)) // All mobs have a multiplier and a size according to mob_defines.dm
 		var/mob/I = AM
 		tforce = I.mob_size * (speed/THROWFORCE_SPEED_DIVISOR)
-	else
-		var/obj/O = AM
+	else if(isitem(AM))
+		var/obj/item/O = AM
 		tforce = O.throwforce * (speed/THROWFORCE_SPEED_DIVISOR)
 	if (tforce < 15)
 		return