removed a redundant (and malicious) write barrier in the GC

git-svn-id: https://svn.inf.ethz.ch/svn/lecturers/a2/trunk@7540 8c9fc860-2736-0410-a75d-ab315db34111

source/Heaps.Mod

@@ -679,7 +679,7 @@ BEGIN
 END GetFreeBlock;
 
 (* Sweep phase *)
-PROCEDURE LazySweep(size: ADDRESS; VAR p: FreeBlock);
+PROCEDURE LazySweep(size: ADDRESS; VAR p {UNTRACED}: FreeBlock);
 VAR 
 	lastFreeBlockAdr: ADDRESS;
 	lastFreeBlockSize: ADDRESS;