- removed a few direct uses of TThinkerIterator.

src/p_mobj.cpp

@@ -5136,7 +5136,7 @@ AActor *FLevelLocals::SpawnPlayer (FPlayerStart *mthing, int playernum, int flag
 			// monsters who last targeted this player will wake up immediately
 			// after the player has respawned.
 			AActor *th;
-			TThinkerIterator<AActor> it;
+			auto it = GetThinkerIterator<AActor>();
 			while ((th = it.Next()))
 			{
 				if (th->LastHeard == oldactor) th->LastHeard = nullptr;

src/portal.cpp

@@ -1035,7 +1035,7 @@ void FLevelLocals::CreateLinkedPortals()
 	if (linkedPortals.Size() > 0)
 	{
 		// We need to relink all actors that may touch a linked line portal
-		TThinkerIterator<AActor> it;
+		auto it = Level->GetThinkerIterator<AActor>();
 		AActor *actor;
 		while ((actor = it.Next()))
 		{

src/statistics.cpp

@@ -413,7 +413,7 @@ static void StoreLevelStats(FLevelLocals *Level)
 
 		// Check for living monsters. On some maps it can happen
 		// that the counter misses some. 
-		TThinkerIterator<AActor> it;
+		auto it = Level->GetThinkerIterator<AActor>();
 		AActor *ac;
 		int mc = 0;