assertions to get errors when first touching the destroyed handle
instead of getting the error when allocating a new handle at some
later point.
Review URL: http://codereview.chromium.org/9741

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@725 ce2b1a6d-e550-0410-aec6-3dcde31c8c00