- account code objects in retainers profile;
- differentiate between function boilerplates and closures;
- simplify code;

Review URL: http://codereview.chromium.org/335016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3124 ce2b1a6d-e550-0410-aec6-3dcde31c8c00