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

compiler/testData/codegen/light-analysis/objects/kt1047.txt

@@ -1,7 +1,9 @@
+@kotlin.Metadata
 public final class Kt1047Kt {
     public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
 }
 
+@kotlin.Metadata
 public class Test {
     public final static field Companion: Test.Companion
     private final static field hello: java.lang.String
@@ -10,6 +12,7 @@ public class Test {
     public method test(): void
 }
 
+@kotlin.Metadata
 public final static class Test/Companion {
     inner class Test/Companion
     private method <init>(): void