The 515 MegaPR early downport (#7783)

Co-authored-by: Selis <selis@xynolabs.com>
Co-authored-by: Selis <sirlionfur@hotmail.de>
Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>
Co-authored-by: SatinIsle <thesatinisle@gmail.com>
Co-authored-by: Heroman <alesha3000@list.ru>
Co-authored-by: Casey <a.roaming.shadow@gmail.com>
Co-authored-by: Raeschen <rycoop29@gmail.com>

code/modules/organs/organ_external.dm

@@ -88,16 +88,21 @@
 
 	if(parent && parent.children)
 		parent.children -= src
+		parent = null
 
 	if(children)
 		for(var/obj/item/organ/external/C in children)
+			children -= C
+			C.parent = null
 			qdel(C)
 
 	if(internal_organs)
 		for(var/obj/item/organ/O in internal_organs)
+			internal_organs -= O
 			qdel(O)
 
 	if(splinted && splinted.loc == src)
+		splinted.loc = null
 		qdel(splinted)
 	splinted = null