1. anchor is a float outside the CB:     target at 120,0 (float 40,0, cb 120,0)
2. CB is a float, anchor outside it:     target at 50,90 (anchor 0,60, cb 50,90)
3. anchor in sibling subtree inside CB:  target at 90,170 (anchor 30,150)
4. anchor is the CB itself:              target at 0,230 (cb 0,230)
5. CB is the ICB, anchor in plain divs:  target at 25,300 (anchor 25,280)
6. duplicate --c6, later one outside CB: target at 15,320 (inside 15,300, outside 0,360)
7. unacceptable anchor with fallback:    target at 44,448 (cb 0,415)
