Do not generate underlying classes for enum entries without member declarations.

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/BodyGenerator.kt

@@ -198,8 +198,7 @@ class BodyGenerator(val scopeOwner: DeclarationDescriptor, override val context:
     }
 
     fun generateEnumEntryInitializer(ktEnumEntry: KtEnumEntry, enumEntryDescriptor: ClassDescriptor): IrExpression {
-        // Enum entry with body has a corresponding underlying class
-        if (ktEnumEntry.getBody() != null) {
+        if (ktEnumEntry.declarations.isNotEmpty()) {
             val enumEntryConstructor = enumEntryDescriptor.unsubstitutedPrimaryConstructor!!
             return IrEnumConstructorCallImpl(ktEnumEntry.startOffset, ktEnumEntry.endOffset,
                                              enumEntryConstructor, enumEntryDescriptor)

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ClassGenerator.kt

@@ -124,7 +124,7 @@ class ClassGenerator(val declarationGenerator: DeclarationGenerator) : Generator
                 BodyGenerator(enumEntryDescriptor.containingDeclaration, context)
                         .generateEnumEntryInitializer(ktEnumEntry, enumEntryDescriptor)
 
-        if (ktEnumEntry.getBody() != null) {
+        if (ktEnumEntry.declarations.isNotEmpty()) {
             irEnumEntry.correspondingClass = generateClass(ktEnumEntry)
         }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrDelegate.kt

@@ -18,7 +18,6 @@ package org.jetbrains.kotlin.ir.declarations
 
 import org.jetbrains.kotlin.descriptors.VariableDescriptor
 import org.jetbrains.kotlin.ir.*
-import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 
@@ -75,6 +74,6 @@ class IrDelegateImpl(
     }
 
     override fun <D> acceptChildren(visitor: IrElementVisitor<Unit, D>, data: D) {
-        initializer?.accept(visitor, data)
+        initializer.accept(visitor, data)
     }
 }

compiler/testData/ir/irText/classes/enum.kt

@@ -5,7 +5,7 @@ enum class TestEnum1 {
 enum class TestEnum2(val x: Int) {
     TEST1(1),
     TEST2(2),
-    TEST3(3)
+    TEST3(3) {}
 }
 
 enum class TestEnum3 {