Add test case

Author: odersky

tests/pos/conformsWild.scala

@@ -0,0 +1,11 @@
+object Test {
+
+  val x: Function1[_, _] = (x: String) => 1
+
+  val y: Function1[_, _] = x => 1
+  val y0: Function1[_, _] = x => x
+  val y1: Function1[_, Nothing] = x => x
+
+  val z: (_, _) = (1, 2)
+
+}