Lua : Fix NativeStringTools.char

std/lua/NativeStringTools.hx

@@ -8,7 +8,7 @@ package lua;
 @:native("_G.string")
 extern class NativeStringTools {
 	public static function len(str : String): Int;
-	public static function char(i: Int): String;
+	public static function char(codes: haxe.extern.Rest<Int>): String;
 	public static function sub(str : String, start : Int, ?end : Int): String;
 	public static function charCodeAt(str : String, index : Int): Int;
 	public static function find(str : String, target : String, ?start : Int, ?plain : Bool): Int;