Fix ClassKind for Serializable and change ClassKind to INTERFACE for error classes.

compiler/backend/src/org/jetbrains/kotlin/codegen/InterfaceImplBodyCodegen.kt

@@ -63,7 +63,7 @@ public class InterfaceImplBodyCodegen(
         if (DescriptorUtils.isLocal(descriptor)) return null
         val classDescriptorImpl = ClassDescriptorImpl(
                 descriptor, Name.identifier(JvmAbi.DEFAULT_IMPLS_CLASS_NAME),
-                Modality.FINAL, Collections.emptyList(), SourceElement.NO_SOURCE)
+                Modality.FINAL, ClassKind.CLASS, Collections.emptyList(), SourceElement.NO_SOURCE)
 
         classDescriptorImpl.initialize(MemberScope.Empty, emptySet(), null)
         return classDescriptorImpl

compiler/backend/src/org/jetbrains/kotlin/codegen/SamWrapperCodegen.java

@@ -70,6 +70,7 @@ public class SamWrapperCodegen {
                 samType.getJavaClassDescriptor().getContainingDeclaration(),
                 fqName.shortName(),
                 Modality.FINAL,
+                ClassKind.CLASS,
                 Collections.singleton(samType.getType()),
                 SourceElement.NO_SOURCE
         );

compiler/backend/src/org/jetbrains/kotlin/codegen/binding/CodegenAnnotatingVisitor.java

@@ -98,6 +98,7 @@ class CodegenAnnotatingVisitor extends KtVisitorVoid {
                 correctContainerForLambda(callableDescriptor, element),
                 Name.special("<closure-" + simpleName + ">"),
                 Modality.FINAL,
+                ClassKind.CLASS,
                 supertypes,
                 KotlinSourceElementKt.toSourceElement(element)
         );