* all "living" nodes into a living block. That's why we must
* move nodes in dead block with "live" successors into a valid
* block.
* all "living" nodes into a living block. That's why we must
* move nodes in dead block with "live" successors into a valid
* block.
* in case of a Phi into the effective use block). For Phi successors,
* this may still be a dead block, but then there is no real use, as
* the control flow will be dead later.
* in case of a Phi into the effective use block). For Phi successors,
* this may still be a dead block, but then there is no real use, as
* the control flow will be dead later.