Load Java enums as final classes

In case Java enum has an abstract member, it has the ACC_ABSTRACT flag
set in the bytecode. However, we should still load it with final
modality to be consistent with Kotlin enums which are always considered
final

 #KT-23426 Fixed

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaClassDescriptor.kt

@@ -72,7 +72,7 @@ class LazyJavaClassDescriptor(
     }
 
     private val modality =
-        if (jClass.isAnnotationType) Modality.FINAL
+        if (jClass.isAnnotationType || jClass.isEnum) Modality.FINAL
         else Modality.convertFromFlags(jClass.isAbstract || jClass.isInterface, !jClass.isFinal)
 
     private val visibility = jClass.visibility