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

compiler/testData/codegen/light-analysis/reified/DIExample.txt

@@ -1,3 +1,4 @@
+@kotlin.Metadata
 public final class DIExampleKt {
     private synthetic final static field $$delegatedProperties: kotlin.reflect.KProperty[]
     private final static @org.jetbrains.annotations.NotNull field project: Project
@@ -10,6 +11,7 @@ public final class DIExampleKt {
     public final static @org.jetbrains.annotations.NotNull method getX2(): java.lang.String
 }
 
+@kotlin.Metadata
 public final class Project {
     public method <init>(): void
     public final method getInstance(@org.jetbrains.annotations.NotNull p0: java.lang.Class): java.lang.Object