JVM IR: fix ::class reference and type mapping for scripts

#KT-46284 Fixed

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/IrTypeMapper.kt

@@ -101,6 +101,12 @@ class IrTypeMapper(private val context: JvmBackendContext) : KotlinTypeMapperBas
     override fun getClassInternalName(typeConstructor: TypeConstructorMarker): String =
         classInternalName((typeConstructor as IrClassSymbol).owner)
 
+    override fun getScriptInternalName(typeConstructor: TypeConstructorMarker): String {
+        val script = (typeConstructor as IrScriptSymbol).owner
+        val targetClass = script.targetClass ?: error("No target class computed for script: ${script.render()}")
+        return classInternalName(targetClass.owner)
+    }
+
     fun writeFormalTypeParameters(irParameters: List<IrTypeParameter>, sw: JvmSignatureWriter) {
         if (sw.skipGenericSignature()) return
         with(KotlinTypeMapper) {

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/ir/IrUtils.kt

@@ -66,12 +66,11 @@ fun IrType.eraseTypeParameters() = when (this) {
     is IrErrorType -> this
     is IrSimpleType ->
         when (val owner = classifier.owner) {
-            is IrClass -> IrSimpleTypeImpl(
-                classifier,
-                hasQuestionMark,
-                arguments.map { it.eraseTypeParameters() },
-                annotations
-            )
+            is IrScript -> {
+                assert(arguments.isEmpty()) { "Script can't be generic: " + owner.render() }
+                IrSimpleTypeImpl(classifier, hasQuestionMark, emptyList(), annotations)
+            }
+            is IrClass -> IrSimpleTypeImpl(classifier, hasQuestionMark, arguments.map { it.eraseTypeParameters() }, annotations)
             is IrTypeParameter -> {
                 val upperBound = owner.erasedUpperBound
                 IrSimpleTypeImpl(

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -338,6 +338,8 @@ fun ReferenceSymbolTable.referenceClassifier(classifier: ClassifierDescriptor):
     when (classifier) {
         is TypeParameterDescriptor ->
             referenceTypeParameter(classifier)
+        is ScriptDescriptor ->
+            referenceScript(classifier)
         is ClassDescriptor ->
             referenceClass(classifier)
         else ->