Add Before Anonymous Child

This tests for a regression against http://bugzilla.opendarwin.org/show_bug.cgi?id=5868 Crash on HP.com with ToT and Safari 2.0.2 in khtml::RenderContainer::detach().

There should be two 100x100 squares stacked vertically below. The green square should be above the blue square.

---

| | | | | |