Contributed by Mathias Bynens <mathiasb@opera.com>.

TEST=mjsunit/es6/string-html
BUG=v8:2217
LOG=Y
R=arv@chromium.org, yangguo@chromium.org

Review URL: https://codereview.chromium.org/446973004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22955 ce2b1a6d-e550-0410-aec6-3dcde31c8c00