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

compiler/testData/codegen/light-analysis/callableReference/function/nestedConstructorFromClass.txt

@@ -1,9 +1,11 @@
+@kotlin.Metadata
 public final class A {
     inner class A/Nested
     public method <init>(): void
     public final method result(): int
 }
 
+@kotlin.Metadata
 public final static class A/Nested {
     private final field k: int
     private final field o: int
@@ -13,6 +15,7 @@ public final static class A/Nested {
     public final method getO(): int
 }
 
+@kotlin.Metadata
 public final class NestedConstructorFromClassKt {
     public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
 }