Revert "Handle non-JSObject heap objects using slow-path IC stub guarded by the map."

TBR=mstarzinger@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23475039

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16692 ce2b1a6d-e550-0410-aec6-3dcde31c8c00