JS introduce marker annotation

js/js.libraries/src/core/annotations.kt

@@ -29,3 +29,6 @@ native
 public annotation class library(public val name: String = "")
 native
 public annotation class enumerable()
+
+native
+public annotation class marker

js/js.libraries/src/core/dom3.kt

@@ -5505,7 +5505,7 @@ native trait PseudoElement {
 }
 native trait CSS {
 }
-native trait UnionHTMLOptGroupElementOrHTMLOptionElement {
+native marker trait UnionHTMLOptGroupElementOrHTMLOptionElement {
 }
-native trait UnionElementOrMouseEvent {
+native marker trait UnionElementOrMouseEvent {
 }