Representation of interceptor / handler properties are tagged.
Otherwise store ICs will never be initialized, due to lookup->CanHoldValue(value);

BUG=chromium:256330
R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23533012

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16471 ce2b1a6d-e550-0410-aec6-3dcde31c8c00