With Zbkb, a bitreverse can be split into a rev8 and a brev8.
We need some more DAG combines to improve this.
Will you continue to update this patch? or put it later
if put it later. what about add an // TODO: comment in the proper place.
Add FIXMEs to the test cases that need more work.
I'll do it another patch. It's likely going to need changes in a different file.
zbkp -> zbkb?
Fix comment mistake