MIPS: Fix secondary stub cache and add a test for the stub cache lookups.  This is a commit of https://chromiumcodereview.appspot.com/9566004 for Daniel Kalmar

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10885 ce2b1a6d-e550-0410-aec6-3dcde31c8c00