Removed old note about pointer tagging

src/backend/vm.nim

@@ -114,11 +114,7 @@ proc collect*(self: var PeonVM)
 
 proc reallocate*(self: var PeonVM, p: pointer, oldSize: int, newSize: int): pointer =
     ## Simple wrapper around realloc with
-    ## built-in garbage collection. Callers
-    ## should keep in mind that the returned
-    ## pointer is tagged (bit 63 is set to 1)
-    ## and should be passed to untag() before
-    ## being dereferenced or otherwise used
+    ## built-in garbage collection
     self.gc.bytesAllocated.current += newSize - oldSize
     try:
         when debugMem: