The queue is maintained via mark_needed_node, linked via node->next_needed
pointer.
- LAST_NNEDED_NODE points to the end of queue, so it can be maintained in forward
- order. QTY is needed to make it friendly to PCH.
+ LAST_NEEDED_NODE points to the end of queue, so it can be
+ maintained in forward order. QTY is needed to make it friendly to
+ PCH.
During unit-at-a-time compilation we construct the queue of needed variables
twice: first time it is during cgraph construction, second time it is at the