+ /* Discard the saved stack and TSO space.
+ What's going on here: TSOs and StkOs are on the mutables
+ list (mutable things in the old generation). Here, we change
+ them to immutable, so that the scavenger (which chks all
+ mutable objects) can detect their immutability and remove
+ them from the list. Setting to MUTUPLE_VHS as the size is
+ essentially saying "No pointers in here" (i.e., empty).
+
+ Without this change of status, these
+ objects might not really die, probably with some horrible
+ disastrous consequence that we don't want to think about.
+ Will & Phil 95/10
+ */