Unless I clearly need to wake up fully :) it seems this conditional would always evaluate truthily in IE8, which -- because of the `else` on line 281 -- would prevent the "object-defineproperty-domexclusive" test from ever running.  Therefore, the alternative defineProperty shim for IE8-DOM would never be used.  Same goes for line 330.  Is it possible to add a test for a DOM node to the test file?