Update TupleXXL.scala

Author: nicolasstucki

library/src/scala/runtime/TupleXXL.scala

@@ -5,7 +5,7 @@ final class TupleXXL private (es: IArray[Object]) extends Product {
 
   def productElement(n: Int): Any = es(n)
   def productArity: Int = es.length
-  def productPrefix: String = "TupleXXL"
+  override def productPrefix: String = "TupleXXL"
 
   override def toString: String = elems.asInstanceOf[Array[Object]].mkString("(", ",", ")")