This can happen e.g. if all supertypes were on the cycle (A : B, B : A)
-- then SupertypesLoopChecker will cut all supertypes that are on cycle,
leaving set of supertypes empty.
Some clients in the compiler are not ready to work with empty list of
supertypes -- notably, CommonSupertypes.
^KT-23029 Fixed
It helps to get rid of semantics duplicating and fixes known bugs
- SOE in OnlyAbstractMethodFinder.find
- type enhancement for SAM constructors
#KT-11287 Fixed
#KT-11322 Fixed
EA-77989 Fixed