BUG=v8:1602
TEST=new (new v8Locale().createDateTimeFormat()).getWeekdays should return Error not a Null.
Review URL: http://codereview.chromium.org/7647027

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8935 ce2b1a6d-e550-0410-aec6-3dcde31c8c00