in a spilled scope or not.  Also get rid of some spilled scopes
that we don't need any more.  The generators for the %_ functions,
CodeGenerator::Generate*, are now not spilled by default.  Some
of them (IsObject and related) have been converted to register
allocated operation.
Review URL: http://codereview.chromium.org/2368001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4749 ce2b1a6d-e550-0410-aec6-3dcde31c8c00