Revert "rra/zhelenskiy/flattening_impl"

This reverts commit b7f5c039a6.

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/builders/ExpressionHelpers.kt

@@ -53,13 +53,11 @@ fun <T : IrElement> IrStatementsBuilder<T>.irTemporary(
     nameHint: String? = null,
     irType: IrType = value?.type!!, // either value or irType should be supplied at callsite
     isMutable: Boolean = false,
-    origin: IrDeclarationOrigin = IrDeclarationOrigin.IR_TEMPORARY_VARIABLE,
 ): IrVariable {
     val temporary = scope.createTemporaryVariableDeclaration(
         irType, nameHint, isMutable,
         startOffset = startOffset,
-        endOffset = endOffset,
-        origin = origin,
+        endOffset = endOffset
     )
     value?.let { temporary.initializer = it }
     +temporary

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

@@ -43,9 +43,6 @@ interface IrDeclarationOrigin {
     object GENERATED_DATA_CLASS_MEMBER : IrDeclarationOriginImpl("GENERATED_DATA_CLASS_MEMBER")
     object GENERATED_SINGLE_FIELD_VALUE_CLASS_MEMBER : IrDeclarationOriginImpl("GENERATED_SINGLE_FIELD_VALUE_CLASS_MEMBER")
     object GENERATED_MULTI_FIELD_VALUE_CLASS_MEMBER : IrDeclarationOriginImpl("GENERATED_MULTI_FIELD_VALUE_CLASS_MEMBER")
-    object GENERATED_MULTI_FIELD_VALUE_CLASS_PARAMETER : IrDeclarationOriginImpl("GENERATED_MULTI_FIELD_VALUE_CLASS_PARAMETER")
-    object TEMPORARY_MULTI_FIELD_VALUE_CLASS_VARIABLE : IrDeclarationOriginImpl("TEMPORARY_MULTI_FIELD_VALUE_CLASS_VARIABLE")
-    object MULTI_FIELD_VALUE_CLASS_REPRESENTATION_VARIABLE : IrDeclarationOriginImpl("MULTI_FIELD_VALUE_CLASS_REPRESENTATION_VARIABLE")
     object LOCAL_FUNCTION : IrDeclarationOriginImpl("LOCAL_FUNCTION")
     object LOCAL_FUNCTION_FOR_LAMBDA : IrDeclarationOriginImpl("LOCAL_FUNCTION_FOR_LAMBDA")
     object CATCH_PARAMETER : IrDeclarationOriginImpl("CATCH_PARAMETER")

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

@@ -128,7 +128,7 @@ abstract class DataClassMembersGenerator(
         fun generateEqualsMethodBody(properties: List<IrProperty>) {
             val irType = irClass.defaultType
 
-            if (!irClass.isValue) {
+            if (!irClass.isSingleFieldValueClass) {
                 +irIfThenReturnTrue(irEqeqeq(irThis(), irOther()))
             }
             +irIfThenReturnFalse(irNotIs(irOther(), irType))