- moved main polyobject array into FLevelLocals and simplified the setup process to not depend on P_SpawnMapThing.

Since the SpawnedThings array is still available when polyobjects are spawned it makes no sense to create an expensive linked list in P_SpawnMapThing.
This can be done far better by scanning through the array again and collect all matching items in a second array.

src/maploader/maploader.cpp

@@ -108,6 +108,8 @@ TArray<FMapThing> MapThingsConverted;
 bool ForceNodeBuild;
 
 
+void PO_Init();
+
 #define MISSING_TEXTURE_WARN_LIMIT		20
 
 void BloodCrypt (void *data, int key, int len);