Add flag to test harness to stop sorting test cases.

R=jkummerow@chromium.org, machenbach@chromium.org

Review URL: https://codereview.chromium.org/307553003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21561 ce2b1a6d-e550-0410-aec6-3dcde31c8c00