Custom reference class instantiation from within other GDNative classs stopped working

[xDGameStudios]

This is related to #253!
It used to be possible to instantiate a Reference in the GDNative side using:

return Ref<B>::__internal_constructor(B::_new())

now this doesn't working anymore (it compiles) but crashes when running in Godot 3.1 stable.

@karroffel (I talked with you about this some time ago.. and it was you that said to use this "snippet".. what do you suggest as alternative now?)

[follower]

As of ~ 9eceb16 the __internal_constructor() workaround should no longer be necessary and use of it may lead to crash, this should now work correctly:

• Ref<CustomClass> ref = Ref<CustomClass>(custom_class_instance);

See #417 for more details.