Change test script to make it easy to run crankshaft tests on ARM and

Change test script to make it easy to run crankshaft tests on ARM and
x64 where crankshaft is not the default. Add ability to add custom
expectations for running in this special crankshaft mode.

The expectations are not updated in this change. There are a couple of
bugs that I would like to fix before doing that. Otherwise the lists
will be very long. :)

Review URL: http://codereview.chromium.org/5787001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5962 ce2b1a6d-e550-0410-aec6-3dcde31c8c00