Add popcount

test/Jamfile.v2

@@ -230,6 +230,7 @@ run bit_width_test.cpp ;
 run has_single_bit_test.cpp ;
 run bit_floor_test.cpp ;
 run bit_ceil_test.cpp ;
+run bit_popcount_test.cpp ;
 
 use-project /boost/core/swap : ./swap ;
 build-project ./swap ;