Penalize hanging pieces

Passed both STC
LLR: 2.95 (-2.94,2.94) [-1.50,4.50]
Total: 8519 W: 1565 L: 1440 D: 5514

And LTC
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 60618 W: 9141 L: 8777 D: 42700

bench: 8678654
Fix a compile error with Intel C++

Intel compiler is very picky:
"error: this operation on an enumerated type requires an
applicable user-defined operator function"

Reported by Tony Gaor.

No functional change.
Merge branch 'master' into queening_square