Reporting uncaught errors at the boundary between C++ and JS instead of trying to guess whether they get caught at the time of the throw.
Review URL: http://codereview.chromium.org/12901

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@915 ce2b1a6d-e550-0410-aec6-3dcde31c8c00