R=danno@chromium.org
TEST=mjsunit/compare-known-objects-slow

Review URL: https://chromiumcodereview.appspot.com/10548046

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11815 ce2b1a6d-e550-0410-aec6-3dcde31c8c00