Before this commit, we added Enum.entries only in case when
LanguageFeature.EnumEntries was ON (with an exception in K1/Java case).
In this commit we add Enum.entries unconditionally, and in case
the language feature is OFF we filter them out during tower resolve.
As a temporary measure before 'javaClass' property is deprecated and removed.
Getting the Java class of a singleton this way is confusing and most of the
time is a failed attempt to get the Java class of a class with a companion
object (e.g. 'Int.javaClass')