// head must be TSO and the head of a linked list of TSOs.
// Shoule it be a child? Seems to be yes.
*first_child = (StgClosure *)((StgMVar *)c)->head;
// head must be TSO and the head of a linked list of TSOs.
// Shoule it be a child? Seems to be yes.
*first_child = (StgClosure *)((StgMVar *)c)->head;