It inadvertently introduced some performance regressions, e.g. for the
'richards' benchmark.

Review URL: https://chromiumcodereview.appspot.com/10704127

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12023 ce2b1a6d-e550-0410-aec6-3dcde31c8c00