Bitwise operator overloads between Bitboard and Square

Yes, we try to be fancy here ;-)

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/pawns.cpp

@@ -188,7 +188,7 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
       // full attack info to evaluate passed pawns. Only the frontmost passed
       // pawn on each file is considered a true passed pawn.
       if (passed && !doubled)
-          set_bit(&(pi->passedPawns[Us]), s);
+          pi->passedPawns[Us] |= s;
 
       // Score this pawn
       if (isolated)