JS stdlib api test: various changes

- Setting -Doverwrite.output=true updates gold data
- Big packages don't get split into chunks
- Unique lines in the API are marked with /*∆*/ and diff test is removed
- Annotations on separate lines and other dump format tweaks
- Test data moved to libraries/stdlib/api/
- Minor visibility fix to Enum members

libraries/stdlib/api/js/kotlin.jvm.kt

@@ -0,0 +1,11 @@
+@kotlin.annotation.Target(allowedTargets = {AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER})
+@kotlin.annotation.Retention(value = AnnotationRetention.SOURCE)
+public final annotation class Synchronized : kotlin.Annotation {
+    public constructor Synchronized()
+}
+
+@kotlin.annotation.Target(allowedTargets = {AnnotationTarget.FIELD})
+@kotlin.annotation.Retention(value = AnnotationRetention.SOURCE)
+public final annotation class Volatile : kotlin.Annotation {
+    public constructor Volatile()
+}