Revert "Remove an unnecessary finger check when re-marking roots."

This reverts commit 6e02fef780c8a122a2ecd3d7afffe962d50d3838.
diff --git a/vm/alloc/MarkSweep.c b/vm/alloc/MarkSweep.c
index adfd555..095e2c7 100644
--- a/vm/alloc/MarkSweep.c
+++ b/vm/alloc/MarkSweep.c
@@ -266,7 +266,7 @@
     assert(arg != NULL);
     obj = *(Object **)addr;
     if (obj != NULL) {
-        markObjectNonNull(obj, arg, false);
+        markObjectNonNull(obj, arg, true);
     }
 }