Fix PromiseHasRejectHandler.

The odd-numbered items in the queue are deferred objects, not promises.

R=aandrey@chromium.org

Review URL: https://codereview.chromium.org/473803003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23143 ce2b1a6d-e550-0410-aec6-3dcde31c8c00