Make enum entries initialize before companion object. This helps
in situation when companion object initializer refers to enum fields.
JVM be generates <clinit> method which first initializes all enum fields
and then runs companion object initializer. This commit introduces the
similar behaviour in JS BE. The old behaviour was: initialize companion
object in constructor. In enum, constructor is called to initialize
enum fields, so previously companion object was initialized first,
which is incorrect.
See KT-16745
Pavel Punegov