Add a premonomorphic state to the call target cache.

From a CL by kasperl: https://codereview.chromium.org/162903004/

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/163413003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19402 ce2b1a6d-e550-0410-aec6-3dcde31c8c00