[BitwiseMutation]: Compilability fixes for bitwise mutation

Fixed compilation issues in BitwiseMutation class.

Signed-off-by: Sebastian Lenartowicz <slenarto@uoguelph.ca>
[Two-Point Crossover]: Compilability fixes for two-point crossover

Fixed compilation issues in TwoPointCrossover class.

Signed-off-by: Sebastian Lenartowicz <slenarto@uoguelph.ca>