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

compiler/testData/codegen/light-analysis/dataClasses/nonTrivialMemberInSuperClass.txt

@@ -1,3 +1,4 @@
+@kotlin.Metadata
 public abstract class Base {
     public method <init>(): void
     public method equals(@org.jetbrains.annotations.Nullable p0: java.lang.Object): boolean
@@ -5,6 +6,7 @@ public abstract class Base {
     public @org.jetbrains.annotations.NotNull method toString(): java.lang.String
 }
 
+@kotlin.Metadata
 public final class DataClass {
     private final @org.jetbrains.annotations.NotNull field field: java.lang.String
     public method <init>(@org.jetbrains.annotations.NotNull p0: java.lang.String): void
@@ -17,6 +19,7 @@ public final class DataClass {
     public method toString(): java.lang.String
 }
 
+@kotlin.Metadata
 public final class NonTrivialMemberInSuperClassKt {
     public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
 }