Make optimized debug builds compile with all optimizations.

This results in a speed-up of around 30% on all architectures. For local developer builds only. The bots will continue to use level 1 for now.

BUG=
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/88563002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18085 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Increase test runner speed.

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