change NoData internal type to Dynamic (#9008)

std/haxe/NoData.hx

@@ -4,7 +4,6 @@ package haxe;
 	Data type used to indicate the absence of a value, especially in types with
 	type parameters.
 **/
-abstract NoData(Int) {
-	public inline function new()
-		this = 0;
+enum abstract NoData(Null<Dynamic>) from Dynamic {
+	var NoData = null;
 }