Add support for with() with Predicate as argument

[Saljack]

• Version of JMockit that was used: 1.49

• Description of the problem or enhancement request: I want to create a simple argument matcher with lambda as predicate in Expectations. But it isn't possible because method with has as argument Delegate which is not a funcional interface. So my proposal is add a new method into Invocations class:

protected final <T> T with(@Nonnull Predicate<? super T> matcher)

then you will be able to create expectations as (String is used just for examle):

 mock.mockMethod(with((String s) -> s.isEmpty()));

With a Delegate you have to write it as:

mock.mockMethod(with(new Delegate<String>() {

  boolean test(String s) {
    return s.isEmpty();
  }

}));