Add failing test for scala#670.

Author: odersky

tests/pending/pos/t8230a.scala

@@ -0,0 +1,26 @@
+trait Arr[T]
+object Arr {
+  def apply[T](xs: T): Arr[T]    = null
+  def apply(x: Long) : Arr[Long] = null
+}
+
+object I {
+  implicit def arrToTrav[T] (a: Arr[T])   : Traversable[T]    = null
+  implicit def longArrToTrav(a: Arr[Long]): Traversable[Long] = null
+}
+
+object Test {
+  def foo(t: Traversable[Any]) = {}
+
+  object Okay {
+    Arr("1")
+
+    import I.{ arrToTrav, longArrToTrav }
+    foo(Arr("2"))
+  }
+
+  object Fail {
+    import I.arrToTrav
+    foo(Arr("3")) // found String, expected Long
+  }
+}