Another fix for cctest/test-run-machops/RunLoadImmIndex.

TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/430203002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22759 ce2b1a6d-e550-0410-aec6-3dcde31c8c00