common case of a single forward edge (a fall-through).  This includes
exits from deferred code.

The fall-through frame is used, after removing constants and copies
above the high-water mark.
Review URL: http://codereview.chromium.org/113400

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1960 ce2b1a6d-e550-0410-aec6-3dcde31c8c00