In order to hide synthetic property isEmpty from JDK 15, there was
added additional logic in 5cc12b49fc but
it also lead to the fact that now it's impossible to call synthetic
property `declaringClass` on `Enum` as it's in the same list as method
isEmpty(). Note that it's questionable behavior, probably we should
also hide `declaringClass` as well but for now we turn it back to
preserve compatibility
#KT-42467 Fixed
Mikhael Bogdanov