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

compiler/testData/codegen/light-analysis/jvmStatic/simple.txt

@@ -1,3 +1,4 @@
+@kotlin.Metadata
 public final class A {
     public final static field INSTANCE: A
     private final static @org.jetbrains.annotations.NotNull field b: java.lang.String
@@ -13,6 +14,7 @@ public final class A {
     public final static @kotlin.jvm.JvmStatic @org.jetbrains.annotations.NotNull method test5(@org.jetbrains.annotations.NotNull p0: java.lang.String): java.lang.String
 }
 
+@kotlin.Metadata
 public final class SimpleKt {
     public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
 }