Also changed a few other places that looked suspicious in the same way.
Added more info to failing test case and rewrote incorrect uses of mjsunit "fail" function.

Review URL: http://codereview.chromium.org/155279


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2409 ce2b1a6d-e550-0410-aec6-3dcde31c8c00