IR: make extractedLocalClasses a JS-only field

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/BackendContext.kt

@@ -30,6 +30,5 @@ interface BackendContext {
     val irBuiltIns: IrBuiltIns
     val sharedVariablesManager: SharedVariablesManager
     val internalPackageFqn: FqName
-    val extractedLocalClasses: MutableSet<IrClass>
     val irFactory: IrFactory
 }

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalClassPopupLowering.kt

@@ -8,18 +8,17 @@ package org.jetbrains.kotlin.backend.common.lower
 import org.jetbrains.kotlin.backend.common.*
 import org.jetbrains.kotlin.backend.common.ir.addChild
 import org.jetbrains.kotlin.backend.common.ir.setDeclarationsParent
-import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.IrBody
 import org.jetbrains.kotlin.ir.expressions.IrStatementContainer
 import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
-import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
-import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
-import org.jetbrains.kotlin.ir.visitors.acceptVoid
 
 //This lower takes part of old LocalDeclarationLowering job to pop up local classes from functions
-open class LocalClassPopupLowering(val context: BackendContext) : BodyLoweringPass {
+open class LocalClassPopupLowering(
+    val context: BackendContext,
+    val recordExtractedLocalClasses: BackendContext.(IrClass) -> Unit = {},
+) : BodyLoweringPass {
     override fun lower(irFile: IrFile) {
         runOnFilePostfix(irFile, withLocalDeclarations = true, allowDeclarationModification = true)
     }
@@ -78,20 +77,7 @@ open class LocalClassPopupLowering(val context: BackendContext) : BodyLoweringPa
                 }
                 else -> error("Inexpected container type $newContainer")
             }
-
-            local.acceptVoid(object : IrElementVisitorVoid {
-                override fun visitElement(element: IrElement) {
-                    element.acceptChildrenVoid(this)
-                }
-
-                override fun visitBody(body: IrBody) {
-                }
-
-                override fun visitClass(declaration: IrClass) {
-                    super.visitClass(declaration)
-                    context.extractedLocalClasses += declaration
-                }
-            })
+            context.recordExtractedLocalClasses(local)
         }
     }
 

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/inline/LocalClasses.kt

@@ -125,7 +125,10 @@ class LocalClassesInInlineFunctionsLowering(val context: CommonBackendContext) :
     }
 }
 
-class LocalClassesExtractionFromInlineFunctionsLowering(context: CommonBackendContext) : LocalClassPopupLowering(context) {
+class LocalClassesExtractionFromInlineFunctionsLowering(
+    context: CommonBackendContext,
+    recordExtractedLocalClasses: BackendContext.(IrClass) -> Unit = {},
+) : LocalClassPopupLowering(context, recordExtractedLocalClasses) {
     private val classesToExtract = mutableSetOf<IrClass>()
 
     override fun lower(irBody: IrBody, container: IrDeclaration) {