log2 is tricky because there cannot be a move between complex1 and
postlog2. We can't guarantee that scheduling complex1 will succeed when
we schedule postlog2, so we try to schedule complex1 and if it fails we
back out by rewriting the postlog2 as a move and introducing a new
postlog2 so that we can try again later.

Signed-off-by: Connor Abbott <cwabbott0@gmail.com>
Acked-by: Qiang Yu <yuq825@gmail.com>