And we should insert fast "should GC?" checks on loop backedges and function exits, of any code that could GC but not clobber world. Those insertion points should be computed before SSA conversion, so that SSA could create loops without worrying about creating new GC points.
This can be viewed as an alternate solution to most of the issues that https://bugs.webkit.org/show_bug.cgi?id=142921 would fix.
One of the nice things about this is that it will allow us to do more store barrier elimination.