Kapt3: Write stub class files with metadata (needed for incremental compilation)

compiler/testData/codegen/light-analysis/fakeOverride/function.txt

@@ -1,54 +1,68 @@
+@kotlin.Metadata
 public class A {
     public method <init>(): void
     public method foo(): void
 }
 
+@kotlin.Metadata
 public final class B {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class C {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class D {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class E {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class F {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class FunctionKt {
     public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
 }
 
+@kotlin.Metadata
 public final class G {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class H {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class I {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class J {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final class K {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public interface T {
     public abstract method foo(): void
 }
 
+@kotlin.Metadata
 public interface U