PSA: Mojo C++ interface bindings changes

[Vardhan Mudunuru]

Hi,

As per https://github.com/domokit/mojo/issues/662 (and a previous email thread on mojo-dev@), I pushed a change that generates interfaces bindings that work ontop of InterfaceHandle<> (formerly InterfacePtrInfo<>) instead of InterfacePtr<>.

This now means that service implementors will need to create an InterfacePtr<> explicitly from InterfaceHandle<>.  Example:

interface A {

  MethodA();

}

interface B {

  MethodB(A a);
}

C++ service implementation from before this change:

class BImpl : public B {

  ...

  // APtr is a typedef for "InterfacePtr<A>"

  MyMethodB(APtr a) { a->MethodA(); }
}

C++ service implementation after this change:

class BImpl : public B {

  // ...

  MyMethodB(InterfaceHandle<A> a) {

    auto a_ptr = APtr::Create(std::move(a));

    a_ptr->MethodA();

  }
}