performance optimizations:

- classes for object/class object and function literals are final
- class objects call own methods via this in oppose to static field in parent

compiler/backend/src/org/jetbrains/jet/codegen/ClosureCodegen.java

@@ -90,7 +90,7 @@ public class ClosureCodegen extends GenerationStateAware {
 
         cv.defineClass(fun,
                        V1_6,
-                       ACC_PUBLIC/*|ACC_SUPER*/,
+                       ACC_PUBLIC|ACC_FINAL/*|ACC_SUPER*/,
                        name.getInternalName(),
                        null,
                        funClass.getInternalName(),

compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -1864,14 +1864,13 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
             ClassReceiver classReceiver = (ClassReceiver) descriptor;
             ClassDescriptor classReceiverDeclarationDescriptor = classReceiver.getDeclarationDescriptor();
             if (DescriptorUtils.isClassObject(classReceiverDeclarationDescriptor)) {
-                ClassDescriptor containingDeclaration = (ClassDescriptor) classReceiverDeclarationDescriptor.getContainingDeclaration();
-                Type classObjType = typeMapper.mapType(containingDeclaration.getDefaultType(), JetTypeMapperMode.IMPL);
-                if (context.getContextDescriptor() instanceof ConstructorDescriptor &&
-                    classReceiverDeclarationDescriptor.getDefaultType()
-                            .equals(((ConstructorDescriptor) context.getContextDescriptor()).getReturnType())) {
-                    v.load(0, classObjType);
+                if (context.getContextDescriptor() instanceof FunctionDescriptor &&
+                    classReceiverDeclarationDescriptor == context.getContextDescriptor().getContainingDeclaration()) {
+                    v.load(0, OBJECT_TYPE);
                 }
                 else {
+                    ClassDescriptor containingDeclaration = (ClassDescriptor) classReceiverDeclarationDescriptor.getContainingDeclaration();
+                    Type classObjType = typeMapper.mapType(containingDeclaration.getDefaultType(), JetTypeMapperMode.IMPL);
                     v.getstatic(classObjType.getInternalName(), "$classobj", exprType.getDescriptor());
                 }
                 StackValue.onStack(exprType).put(type, v);

compiler/backend/src/org/jetbrains/jet/codegen/ImplementationBodyCodegen.java

@@ -107,6 +107,10 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                 isEnum = true;
             }
 
+            if(descriptor.getKind() == ClassKind.OBJECT || descriptor.getKind() == ClassKind.CLASS_OBJECT) {
+                isFinal = true;
+            }
+
             if (!jetClass.hasModifier(JetTokens.OPEN_KEYWORD) && !isAbstract) {
                 isFinal = true;
             }