Fix patching the receiver (global object -> global proxy) after the interceptor.

This is a temporary fix that will be replaced by loading the proxy from the target function.

R=dcarney@chromium.org

Review URL: https://chromiumcodereview.appspot.com/108913006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18286 ce2b1a6d-e550-0410-aec6-3dcde31c8c00