This is an addition to d4278250e6. Apparently we still need to produce
a new fake override for each inherited static member, because otherwise
we would try to determine the most specific return type, maximum
visibility, etc, all of which makes no sense for static members.
#KT-66152 Fixed
This is needed because in case a static member is inherited via a Kotlin
class (class C in the newly added test), its origin becomes
FAKE_OVERRIDE which is technically not Java anymore. After this change,
we'll build fake overrides for static members from superclasses
regardless of whether they come from Java or Kotlin.
Also, move the previous logic of
isOverridableFunction/isOverridableProperty to the only call site at
IdSignatureFactory.
#KT-65589 Fixed
Alexander Udalov