Adds:
- optimizer/BinaryOperatorOptimizer: optimizes expressions with a binary operator
- assignments will be handled by optimizer/AssignmentOptimizer
- optimizer/BinaryOperatorWithFloatOptimizer: optimizes binary operator expressions with a FloatValue left-hand side
- optimizer/BinaryOperatorWithIntegerOptimizer: optimizes binary operator expressions with an IntegerValue left-hand side
- optimizer/BinaryOperatorWithStringOptimizer: optimizes binary operator expressions with a StringValue left-hand side