Show user script source line that caused exception intead of a line in a native script. When an error is reported as one happened in a native script it's hard to track the original cause. See chromium issue: http://crbug.com/25305
Review URL: http://codereview.chromium.org/555170

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3753 ce2b1a6d-e550-0410-aec6-3dcde31c8c00