[Commonizer] Encapsulate interning inside of CIR entities: CirTypeParameterType

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/CirType.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.descriptors.commonizer.cir
 
 import kotlinx.metadata.KmType
+import org.jetbrains.kotlin.descriptors.commonizer.utils.Interner
 import org.jetbrains.kotlin.types.Variance
 
 typealias CirTypeSignature = String
@@ -46,14 +47,27 @@ sealed class CirSimpleType : CirType() {
     }
 }
 
-data class CirTypeParameterType(
-    val index: Int,
-    override val isMarkedNullable: Boolean
-) : CirSimpleType() {
+abstract class CirTypeParameterType : CirSimpleType() {
+    abstract val index: Int
+
     override fun appendDescriptionTo(builder: StringBuilder) {
         builder.append('#').append(index)
         super.appendDescriptionTo(builder)
     }
+
+    companion object {
+        fun createInterned(
+            index: Int,
+            isMarkedNullable: Boolean
+        ): CirTypeParameterType = interner.intern(
+            CirTypeParameterTypeInternedImpl(
+                index = index,
+                isMarkedNullable = isMarkedNullable
+            )
+        )
+
+        private val interner = Interner<CirTypeParameterTypeInternedImpl>()
+    }
 }
 
 sealed class CirClassOrTypeAliasType : CirSimpleType() {
@@ -111,3 +125,8 @@ data class CirTypeProjectionImpl(val projectionKind: Variance, val type: CirType
         type.appendDescriptionTo(this)
     }
 }
+
+private data class CirTypeParameterTypeInternedImpl(
+    override val index: Int,
+    override val isMarkedNullable: Boolean
+) : CirTypeParameterType()

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/factory/CirAnnotationFactory.kt

@@ -34,7 +34,7 @@ object CirAnnotationFactory {
             arguments = clazz.typeParameters.compactMap { typeParameter ->
                 CirTypeProjectionImpl(
                     projectionKind = typeParameter.variance,
-                    type = CirTypeFactory.createTypeParameterType(
+                    type = CirTypeParameterType.createInterned(
                         index = typeParameter.index,
                         isMarkedNullable = false
                     )

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/factory/CirTypeFactory.kt

@@ -32,7 +32,6 @@ object CirTypeFactory {
 
     private val classTypeInterner = Interner<CirClassType>()
     private val typeAliasTypeInterner = Interner<CirTypeAliasType>()
-    private val typeParameterTypeInterner = Interner<CirTypeParameterType>()
 
     fun create(source: KmType, typeResolver: CirTypeResolver): CirType {
         @Suppress("NAME_SHADOWING")
@@ -76,7 +75,7 @@ object CirTypeFactory {
                 )
             }
             is KmClassifier.TypeParameter -> {
-                createTypeParameterType(
+                CirTypeParameterType.createInterned(
                     index = typeResolver.resolveTypeParameterIndex(classifier.id),
                     isMarkedNullable = isMarkedNullable
                 )
@@ -118,19 +117,6 @@ object CirTypeFactory {
         )
     }
 
-    @Suppress("MemberVisibilityCanBePrivate")
-    fun createTypeParameterType(
-        index: Int,
-        isMarkedNullable: Boolean
-    ): CirTypeParameterType {
-        return typeParameterTypeInterner.intern(
-            CirTypeParameterType(
-                index = index,
-                isMarkedNullable = isMarkedNullable
-            )
-        )
-    }
-
     fun <T : CirSimpleType> makeNullable(type: T): T {
         if (type.isMarkedNullable)
             return type
@@ -149,7 +135,7 @@ object CirTypeFactory {
                 arguments = type.arguments,
                 isMarkedNullable = true
             )
-            is CirTypeParameterType -> createTypeParameterType(
+            is CirTypeParameterType -> CirTypeParameterType.createInterned(
                 index = type.index,
                 isMarkedNullable = true
             )