trace compare_nil_ic state in --trace-ic output

BUG=
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/15735020

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14808 ce2b1a6d-e550-0410-aec6-3dcde31c8c00