made ActiveCellsRuntime working on 64-bit platforms: use offset dependent on the bitwidth of the address

git-svn-id: https://svn.inf.ethz.ch/svn/lecturers/a2/trunk@7648 8c9fc860-2736-0410-a75d-ab315db34111

source/ActiveCellsRuntime.mod

@@ -156,7 +156,7 @@ type
 
 		(* allocation of cells must use the tag provided, it contains all internally stored metadata *)
 		Heaps.NewRec(a, tag, false);
-		system.get(tag-4,typeInfo);
+		system.get(tag-sizeof(address),typeInfo);
 
 		if EnableTrace then trace(scope, c, typeInfo, name, isCellnet, isEngine); end;