Retire direction.cpp

Move the code to bitboard.cpp

No functional change.

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

src/Makefile

@@ -35,7 +35,7 @@ PGOBENCH = ./$(EXE) bench 32 1 10 default depth
 ### Object files
 OBJS = bitboard.o pawns.o material.o endgame.o evaluate.o main.o \
 	misc.o move.o movegen.o history.o movepick.o search.o position.o \
-	direction.o tt.o uci.o ucioption.o book.o bitbase.o san.o benchmark.o timeman.o
+	tt.o uci.o ucioption.o book.o bitbase.o san.o benchmark.o timeman.o
 
 
 ### ==========================================================================