Codegen had a bug where if you emit a block in astubs that
has a getNext() which is also in astubs, it would omit the jump.
However, it might visit another block in a first, which is allowed to
put code in astubs. Generally the block order was just defined by the
order that happened to be in the block list by the time we get there.
Change it to emit blocks in the RPO defined by sortCfg for now, after
partitioning them into groups for a and astubs. This fixes the bug,
and at least makes codegen use a defined order. We later will
probably want to see about whether we may be able to avoid more jumps
with smarter layout.
Jordan DeLong
4f3c0c15b4