IR: reorganize IrProvider handling

Make DeclarationStubGenerator a subclass of IrProvider,
anticipating deserialization of IR structures for JVM_IR backend.

compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.util.ExpectDeclarationRemover
 import org.jetbrains.kotlin.ir.util.IrDeserializer
 import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.ir.util.generateTypicalIrProviderList
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.js.analyzer.JsAnalysisResult
 import org.jetbrains.kotlin.js.config.JSConfigurationKeys
@@ -201,7 +202,8 @@ fun GeneratorContext.generateModuleFragmentWithPlugins(
     files: List<KtFile>,
     deserializer: IrDeserializer? = null
 ): IrModuleFragment {
-    val psi2Ir = Psi2IrTranslator(languageVersionSettings, configuration)
+    val irProviders = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable, deserializer)
+    val psi2Ir = Psi2IrTranslator(languageVersionSettings, configuration, mangler = JsMangler)
 
     for (extension in IrGenerationExtension.getInstances(project)) {
         psi2Ir.addPostprocessingStep { module ->
@@ -223,13 +225,17 @@ fun GeneratorContext.generateModuleFragmentWithPlugins(
         psi2Ir.generateModuleFragment(
             this,
             files,
-            deserializer
+            irProviders
         )
     return moduleFragment
 }
 
-fun GeneratorContext.generateModuleFragment(files: List<KtFile>, deserializer: IrDeserializer? = null) =
-    Psi2IrTranslator(languageVersionSettings, configuration).generateModuleFragment(this, files, deserializer)
+fun GeneratorContext.generateModuleFragment(files: List<KtFile>, deserializer: IrDeserializer? = null): IrModuleFragment {
+    val irProviders = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable, deserializer)
+    return Psi2IrTranslator(
+        languageVersionSettings, configuration, mangler = JsMangler
+    ).generateModuleFragment(this, files, irProviders)
+}
 
 
 private fun createBuiltIns(storageManager: StorageManager) = object : KotlinBuiltIns(storageManager) {}