Mozilla Bug 1100912

1. | 3 4 |  | rtl on host
2. | 3 4 |  | rtl on host, ltr slot's parent
3. | 3 4 |  | rtl on host, ltr on slot
4. | 1 2 |  | auto host, rtl in shadow
5. | أخبار |  | auto host, rtl in host (in assigned node)
6. | أخبار |  | auto host, rtl in host, no assigned node
7. | أخبار |  | auto host, rtl in host, explicit ltr in shadow
8. | ‎1 2 أخبار |  | auto host, ltr in host, rtl in host, reverse order in slots
9. | أخبار |  | auto host, rtl in host (in assigned text node)
10. | 1 2 |  | auto host, 1 2 in host (in assigned text node)