A PreDenotation represents a group of single denotations or a single multi-denotation
It is used as an optimization to avoid forming MultiDenotations too eagerly.
Keep only those inherited members M of this predenotation for which the following is true
Keep only those inherited members M of this predenotation for which the following is true
M is not marked Private
If M has a unique symbol, it does not appear in prevDenots.
M's signature as seen from prefix pre does not appear in ownDenots
Return the denotation as seen from pre.
Called from SymDenotations.computeMember. There, ownDenots are the denotations found in
the base class, which shadow any inherited denotations with the same signature.
prevDenots are the denotations that are defined in the class or inherited from
a base type which comes earlier in the linearization.