[K/N] De-duplicate code for mangling objc interop function names

Extract the duplicated functionality to the
`ObjCFunctionNameMangleComputer` class.

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/BaseKotlinMangleComputer.kt

@@ -42,12 +42,12 @@ abstract class BaseKotlinMangleComputer<Declaration, Type, TypeParameter, ValueP
 
     protected val typeParameterContainers = ArrayList<TypeParameterContainer>(4)
 
-    protected open fun FunctionDeclaration.platformSpecificFunctionName(): String? = null
+    protected open fun makePlatformSpecificFunctionNameMangleComputer(
+        function: FunctionDeclaration
+    ): PlatformSpecificFunctionNameMangleComputer<ValueParameter> = PlatformSpecificFunctionNameMangleComputer.Default
 
     protected open fun FunctionDeclaration.platformSpecificSuffix(): String? = null
 
-    protected open fun FunctionDeclaration.specialValueParamPrefix(param: ValueParameter): String = ""
-
     protected open fun addReturnType(): Boolean = false
 
     protected open fun addReturnTypeSpecialCase(function: FunctionDeclaration): Boolean = false
@@ -145,7 +145,7 @@ abstract class BaseKotlinMangleComputer<Declaration, Type, TypeParameter, ValueP
 
         builder.appendName(MangleConstant.FUNCTION_NAME_PREFIX)
 
-        platformSpecificFunctionName()?.let {
+        makePlatformSpecificFunctionNameMangleComputer(this).computePlatformSpecificFunctionName()?.let {
             builder.append(it)
             return
         }
@@ -180,7 +180,10 @@ abstract class BaseKotlinMangleComputer<Declaration, Type, TypeParameter, ValueP
         }
 
         getValueParameters(this).collectForMangler(builder, MangleConstant.VALUE_PARAMETERS) {
-            appendSignature(specialValueParamPrefix(it))
+            appendSignature(
+                makePlatformSpecificFunctionNameMangleComputer(this@mangleSignature)
+                    .computePlatformSpecificValueParameterPrefix(it)
+            )
             mangleValueParameter(this, it, session)
         }
 

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/PlatformSpecificFunctionNameMangleComputer.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.common.serialization.mangle
+
+interface PlatformSpecificFunctionNameMangleComputer<in ValueParameter : Any> {
+
+    fun computePlatformSpecificFunctionName(): String?
+
+    fun computePlatformSpecificValueParameterPrefix(valueParameter: ValueParameter): String
+
+    object Default : PlatformSpecificFunctionNameMangleComputer<Any> {
+
+        override fun computePlatformSpecificFunctionName(): String? = null
+
+        override fun computePlatformSpecificValueParameterPrefix(valueParameter: Any): String = ""
+    }
+}