Changed the way struct/class fields are added, first small part of cleaning up these...
Make struct/class/union fields aware of any anonymous struct/union they might be part of, not yet really useful, but part of getting better union support.
Changed the tryfinally handlers to a more generalized EnclosingHandler.
Changed ClassInfoS to be mutable so they can be used as locks.
Added new BB after throw ala return/break etc.
