I made a test run of benchmarks and found another weak point. After
fixing it, benchmarks are able to run for a 100 times in a row
successfully in both builds.

Review URL: http://codereview.chromium.org/53050

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1612 ce2b1a6d-e550-0410-aec6-3dcde31c8c00