// So, when we thaw a MUT_ARR_PTRS_FROZEN, we must cope with two cases:
// either it is on a mut_list, or it isn't. We adopt the convention that
- // the mut_link field is NULL if it isn't on a mut_list, and the GC
- // maintains this invariant.
+ // the closure type is MUT_ARR_PTRS_FROZEN0 if it is on the mutable list,
+ // and MUT_ARR_PTRS_FROZEN otherwise.
//
if (%INFO_TYPE(%GET_STD_INFO(R1)) != HALF_W_(MUT_ARR_PTRS_FROZEN0)) {
foreign "C" recordMutableLock(R1 "ptr") [R1];