Some follow-up fixes after r23801.

R=rossberg@chromium.org
TEST=mjsunit --turbo-types

Review URL: https://codereview.chromium.org/559563002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23812 ce2b1a6d-e550-0410-aec6-3dcde31c8c00