R=rossberg@chromium.org
TEST=mjsunit/object-is,mjsunit/number-is

Review URL: https://chromiumcodereview.appspot.com/9630009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10965 ce2b1a6d-e550-0410-aec6-3dcde31c8c00