KT-29340 Provide effective modality for enum class in IR

* if enum class has abstract members, then it is ABSTRACT
* otherwise, if enum class has entries with members, then it is OPEN
* otherwise, it is FINAL.

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/impl/IrClassImpl.kt

@@ -53,12 +53,14 @@ class IrClassImpl(
         startOffset: Int,
         endOffset: Int,
         origin: IrDeclarationOrigin,
-        symbol: IrClassSymbol
+        symbol: IrClassSymbol,
+        modality: Modality = symbol.descriptor.modality
     ) :
             this(
                 startOffset, endOffset, origin, symbol,
                 symbol.descriptor.name, symbol.descriptor.kind,
-                symbol.descriptor.visibility, symbol.descriptor.modality,
+                symbol.descriptor.visibility,
+                modality = modality,
                 isCompanion = symbol.descriptor.isCompanionObject,
                 isInner = symbol.descriptor.isInner,
                 isData = symbol.descriptor.isData,
@@ -70,17 +72,19 @@ class IrClassImpl(
         startOffset: Int,
         endOffset: Int,
         origin: IrDeclarationOrigin,
-        descriptor: ClassDescriptor
+        descriptor: ClassDescriptor,
+        modality: Modality = descriptor.modality
     ) :
-            this(startOffset, endOffset, origin, IrClassSymbolImpl(descriptor))
+            this(startOffset, endOffset, origin, IrClassSymbolImpl(descriptor), modality)
 
     constructor(
         startOffset: Int,
         endOffset: Int,
         origin: IrDeclarationOrigin,
         descriptor: ClassDescriptor,
-        members: List<IrDeclaration>
-    ) : this(startOffset, endOffset, origin, descriptor) {
+        modality: Modality = descriptor.modality,
+        members: List<IrDeclaration> = emptyList()
+    ) : this(startOffset, endOffset, origin, descriptor, modality) {
         addAll(members)
     }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTree.kt

@@ -92,6 +92,7 @@ open class DeepCopyIrTree : IrElementTransformerVoid() {
             declaration.startOffset, declaration.endOffset,
             mapDeclarationOrigin(declaration.origin),
             mapClassDeclaration(declaration.descriptor),
+            declaration.modality,
             declaration.declarations.map { it.transform() }
         ).apply {
             transformAnnotations(declaration)

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/SymbolTable.kt

@@ -232,7 +232,8 @@ open class SymbolTable : ReferenceSymbolTable {
 
     fun declareClass(
         startOffset: Int, endOffset: Int, origin: IrDeclarationOrigin, descriptor: ClassDescriptor,
-        classFactory: (IrClassSymbol) -> IrClass = { IrClassImpl(startOffset, endOffset, origin, it) }
+        modality: Modality = descriptor.modality,
+        classFactory: (IrClassSymbol) -> IrClass = { IrClassImpl(startOffset, endOffset, origin, it, modality) }
     ): IrClass {
         return classSymbolTable.declare(
             descriptor,