Add a test case for Phi representations

BUG=chromium:167394
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/18838002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15553 ce2b1a6d-e550-0410-aec6-3dcde31c8c00