Fix #1614: correctly handle polymorphic inner methods
Fix #1614: correctly handle polymorphic inner methods

Even if outer class & method isn't polymorpnic,
inner method might be. Need to handle this correctly.

som-snytt/dotty,lampepfl/dotty,dotty-staging/dotty,dotty-staging/dotty,som-snytt/dotty,sjrd/dotty,sjrd/dotty,lampepfl/dotty,lampepfl/dotty,lampepfl/dotty,som-snytt/dotty,dotty-staging/dotty,lampepfl/dotty,dotty-staging/dotty,sjrd/dotty,som-snytt/dotty,dotty-staging/dotty,som-snytt/dotty,sjrd/dotty,sjrd/dotty