There is no test case to trigger any crash. This is only to guard against the case that the native function is called with unsafe arguments.

Review URL: http://codereview.chromium.org/8554004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10064 ce2b1a6d-e550-0410-aec6-3dcde31c8c00