Add Tuple1 generic constuctor

Author: nicolasstucki

library/src-bootstrapped/scala/Tuple.scala

@@ -160,6 +160,9 @@ object Tuple {
   /** Empty tuple */
   def apply(): EmptyTuple = scala.runtime.Tuple0.asInstanceOf[EmptyTuple]
 
+  /** Tuple with one element */
+  def apply[T](x: T): T *: EmptyTuple = Tuple1(x)
+
   /** Matches an empty tuple. */
   def unapply(x: EmptyTuple): true = true
 

tests/run-deep-subtype/Tuple-toArray.scala

@@ -14,7 +14,7 @@ object Test {
       testArray(i, j => j)
 
     printArray(Tuple().toArray)
-    printArray(Tuple1(1).toArray)
+    printArray(Tuple(1).toArray)
     printArray((1, 2).toArray)
     printArray((1, 2, 3).toArray)
     printArray((1, 2, 3, 4).toArray)