the prototype chain. In case we're skipping a global object,
we have to be careful not to use ICs for the load, because
it's possible to introduce variables on the global object
without a map change.
Review URL: http://codereview.chromium.org/149316

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2385 ce2b1a6d-e550-0410-aec6-3dcde31c8c00