This generates code stubs for cloning of shallow object literal
boilerplates that have no elements and only fast properties. Improves
splay performance because object literals are created frequently.

R=fschneider@chromium.org

Review URL: http://codereview.chromium.org/8598014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10036 ce2b1a6d-e550-0410-aec6-3dcde31c8c00