IR: make IrValueParameter.varargElementType mutable

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

@@ -36,7 +36,7 @@ class IrValueParameterImpl(
     override val name: Name,
     override val index: Int,
     override var type: IrType,
-    override val varargElementType: IrType?,
+    override var varargElementType: IrType?,
     override val isCrossinline: Boolean,
     override val isNoinline: Boolean,
     override val isHidden: Boolean = false

compiler/ir/ir.tree.persistent/src/org/jetbrains/kotlin/ir/declarations/persistent/PersistentIrValueParameter.kt

@@ -38,7 +38,7 @@ internal class PersistentIrValueParameter(
     override val name: Name,
     override val index: Int,
     type: IrType,
-    override val varargElementType: IrType?,
+    varargElementType: IrType?,
     override val isCrossinline: Boolean,
     override val isNoinline: Boolean,
     override val isHidden: Boolean = false
@@ -87,4 +87,13 @@ internal class PersistentIrValueParameter(
             }
         }
 
+    override var varargElementTypeField: IrType? = varargElementType
+
+    override var varargElementType: IrType?
+        get() = getCarrier().varargElementTypeField
+        set(v) {
+            if (varargElementType !== v) {
+                setCarrier().varargElementTypeField = v
+            }
+        }
 }

compiler/ir/ir.tree.persistent/src/org/jetbrains/kotlin/ir/declarations/persistent/carriers/ValueParameterCarrier.kt

@@ -14,10 +14,11 @@ import org.jetbrains.kotlin.ir.types.IrType
 internal interface ValueParameterCarrier : DeclarationCarrier {
     var defaultValueField: IrExpressionBody?
     var typeField: IrType
+    var varargElementTypeField: IrType?
 
     override fun clone(): ValueParameterCarrier {
         return ValueParameterCarrierImpl(
-            lastModified, parentField, originField, annotationsField, defaultValueField, typeField
+            lastModified, parentField, originField, annotationsField, defaultValueField, typeField, varargElementTypeField
         )
     }
 }
@@ -29,4 +30,5 @@ internal class ValueParameterCarrierImpl(
     override var annotationsField: List<IrConstructorCall>,
     override var defaultValueField: IrExpressionBody?,
     override var typeField: IrType,
+    override var varargElementTypeField: IrType?,
 ) : ValueParameterCarrier

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

@@ -29,7 +29,7 @@ abstract class IrValueParameter : IrValueDeclaration(), IrSymbolDeclaration<IrVa
     abstract override val descriptor: ParameterDescriptor
 
     abstract val index: Int
-    abstract val varargElementType: IrType?
+    abstract var varargElementType: IrType?
     abstract val isCrossinline: Boolean
     abstract val isNoinline: Boolean
     // if true parameter is not included into IdSignature.