8071670: java.util.Optional: please add a way to specify if-else behavior
Reviewed-by: dfuchs, lowasser

8050820: Please add java.util.Optional.stream() to convert Optional<T> to Stream<T>
Reviewed-by: alundblad, forax, chegar, jrose

8001642: Add Optional<T>, OptionalDouble, OptionalInt, OptionalLong
Reviewed-by: mduigou, darcy, alanb, jjb
Contributed-by: Brian Goetz <brian.goetz@oracle.com>