IC mangling: Replace compiler hack with configuration flag

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/inlineclasses/InlineClassAbi.kt

@@ -61,8 +61,6 @@ object InlineClassAbi {
         return irClass.primaryConstructor!!.valueParameters[0].type
     }
 
-    private fun IrFunction.isFunctionFromStdlib(): Boolean = fqNameForIrSerialization.startsWith(Name.identifier("kotlin"))
-
     /**
      * Returns a mangled name for a function taking inline class arguments
      * to avoid clashes between overloaded methods.
@@ -99,7 +97,7 @@ object InlineClassAbi {
         alwaysMangleReturnType: Boolean = false
     ): String? {
         val signatureForMangling = collectFunctionSignatureForManglingSuffix(
-            useOldManglingRules = useOldMangleRules || irFunction.isFunctionFromStdlib(),
+            useOldManglingRules = useOldMangleRules,
             requiresFunctionNameManglingForParameterTypes = irFunction.fullValueParameterList.any { it.type.requiresMangling },
             fqNamesForMangling = irFunction.fullValueParameterList.map {
                 it.type.asInfoForMangling()

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/inlineclasses/MemoizedInlineClassReplacements.kt

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.backend.jvm.codegen.classFileContainsMethod
 import org.jetbrains.kotlin.backend.jvm.ir.isStaticInlineClassReplacement
 import org.jetbrains.kotlin.backend.jvm.lower.inlineclasses.InlineClassAbi.mangledNameFor
 import org.jetbrains.kotlin.codegen.state.KotlinTypeMapper
+import org.jetbrains.kotlin.config.JVMConfigurationKeys
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.builders.declarations.addValueParameter
@@ -221,8 +222,13 @@ class MemoizedInlineClassReplacements(
         if (noFakeOverride) {
             isFakeOverride = false
         }
-        name = mangledNameFor(function, mangleReturnTypes, false)
-        if (name.asString().contains("-") && classFileContainsMethod(function, context, name.asString()) == false) {
+        val useOldManglingScheme = context.state.configuration.getBoolean(JVMConfigurationKeys.USE_OLD_INLINE_CLASSES_MANGLING_SCHEME)
+        name = mangledNameFor(function, mangleReturnTypes, useOldManglingScheme)
+        if (
+            !useOldManglingScheme &&
+            name.asString().contains("-") &&
+            classFileContainsMethod(function, context, name.asString()) == false
+        ) {
             name = mangledNameFor(function, mangleReturnTypes, true)
         }
         returnType = function.returnType