Add fixed test case for #3658

Author: odersky

tests/pos/i3658.scala

@@ -0,0 +1,15 @@
+object App {
+  def main(args: Array[String]): Unit = {
+    trait ModuleSig {
+      type F[_]
+      type Type = F
+
+      def subst[F[_[_]]](fa: F[List]): F[Type]
+    }
+    val Module: ModuleSig = new ModuleSig {
+      type F[+A] = List[A]
+
+      def subst[FF[_[_]]](fa: FF[List]): FF[Type] = fa
+    }
+  }
+}