More precisely, add CheckGeneratedRuntimeTests to checks performed by
'git cl presubmit'.

R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/352583005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21970 ce2b1a6d-e550-0410-aec6-3dcde31c8c00