Let the test runner preserve the order of test suites to let suites with long running tests run first.

Mark some tests as slow that can now be skipped via --slow-tests=skip.

BUG=
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/88343002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18086 ce2b1a6d-e550-0410-aec6-3dcde31c8c00