This is a reincarnation of r21841.

The previous try was https://codereview.chromium.org/314603004/ but it regressed
JSBench and morejs.

BUG=
R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/335293004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21972 ce2b1a6d-e550-0410-aec6-3dcde31c8c00