Slot usage is a brittle thing

[mih]

We have noticed annotations not being inherited. Now I saw a multivalued declaration in a derived class not being honored, unless there was a multivalued declaration (regardless of the actual value) in the base class.

Needs a thorough investigation what works and what doesn't. Also to rule out that any of our patches doesn't introduce undesired behaviors.

[mih]

Likely this is caused by or constrained to the handling of annotations coming from mixins. These seem to be largely ignored.