Partial and small update to the codegen to use the new register allocator framework.  See http://codereview.chromium.org/1732024.  Committed for Rodolph Perfetta.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4564 ce2b1a6d-e550-0410-aec6-3dcde31c8c00