A class can inherit two declarations that are compatible from the
overridability standpoint and are therefore combined to a non-trivial
intersection.
At the same time, the class can declare a member declaration that
only overrides one of the intersection's members.
In this case, we break up the intersection and only add the overridden
parts to the declared member's direct overridden list.
If the class doesn't override the intersection, it exists as
intersection override, like before.
#KT-65487 Fixed
Before this commit we took just first intersection member for this check.
However it's quite bad, because we were dependent on supertype order.
Choosing the most specific member looks more consistent here.
#KT-50969 Fixed
Kirill Rakhman