1. Enum entry fields don't have nullability annotations.
2. Enum class special methods (values, valueOf) are not 'final'
(although they probably should be, javac generates corresponding
methods without ACC_FINAL flag).
3. Enum class special methods don't have nullability annotations.
4. Don't generate synthetic accessor for enum entry class constructor.
KT-37019 KT-37020 KT-37021
Dmitry Petrov