Polyobjects: add po_movecount member to mobj_t instead of using lastlook

- Polyobject carrying set lastlook on mobjs for internal
  tracking
- lastlook is used by some objects to track their own
  state
- Ring Shooter uses lastlook to remember which player
  summoned it
- A Ring Shooter spawned right next to a polyobject would
  become buggy; If its owner player pressed the respawn
  button again before the Ring Shooter despawned, that
  player would be teleported back to the Ring Shooter
  instead of spawning a new Ring Shooter (which would be
  the correct behavior)

src/p_mobj.h

@@ -447,6 +447,8 @@ struct mobj_t
 
 	mobj_t *owner;
 
+	INT32 po_movecount; // Polyobject carrying (NOT savegame, NOT Lua)
+
 	// WARNING: New fields must be added separately to savegame and Lua.
 };
 

src/p_polyobj.c

@@ -879,14 +879,10 @@ static void Polyobj_carryThings(polyobj_t *po, fixed_t dx, fixed_t dy)
 
 			for (; mo; mo = mo->bnext)
 			{
-				// lastlook is used by the SPB to determine targets, do not let it affect it
-				if (mo->type == MT_SPB)
+				if (mo->po_movecount == pomovecount)
 					continue;
 
-				if (mo->lastlook == pomovecount)
-					continue;
-
-				mo->lastlook = pomovecount;
+				mo->po_movecount = pomovecount;
 
 				// Don't scroll objects that aren't affected by gravity
 				if (mo->flags & MF_NOGRAVITY)
@@ -1115,14 +1111,10 @@ static void Polyobj_rotateThings(polyobj_t *po, vector2_t origin, angle_t delta,
 
 			for (; mo; mo = mo->bnext)
 			{
-				// lastlook is used by the SPB to determine targets, do not let it affect it
-				if (mo->type == MT_SPB)
+				if (mo->po_movecount == pomovecount)
 					continue;
 
-				if (mo->lastlook == pomovecount)
-					continue;
-
-				mo->lastlook = pomovecount;
+				mo->po_movecount = pomovecount;
 
 				// Don't scroll objects that aren't affected by gravity
 				if (mo->flags & MF_NOGRAVITY)