Here's what we need:
- Register allocation.
- Dead code elimination. We should run this before and after register allocation.
- CFG simplification. At a minium, we should be able to remove blocks that just have a jump.
*** This bug has been marked as a duplicate of bug 154319 ***
I didn't mean to dup it.
We did enough of this, future improvements will be tracked by https://bugs.webkit.org/show_bug.cgi?id=154319