Add test

Author: odersky

tests/pos/export-enum.scala

@@ -0,0 +1,15 @@
+object Signature {
+
+  enum MatchDegree {
+    case NoMatch, ParamMatch, FullMatch
+  }
+  export MatchDegree._
+
+  // Check that exported values have singeleton types
+  val x: MatchDegree.NoMatch.type = NoMatch
+
+  // Check that the following two methods are not exported.
+  // Exporting them would lead to a double definition.
+  def values: Array[MatchDegree] = ???
+  def valueOf($name: String): MatchDegree = ???
+}