Inferred type of receiver of orElse is Optional<T & Any>
Generic descriptor is orElse(E!): E!
Substituted descriptor is orElse(T): T , and that is the problem.
Seems that E! => (T & Any)! gets expanded to just T or T & Any , however it should be expanded to
(T & Any) .. (T & Any)? => T & Any .. T & Any
T & Any is NotNullTypeParameter(T)
The problem is that (T & Any)? is expanded to T & Any,
that is seems to be wrong.
#KT-15236 Fixed