Add WF test for never type

Author: nathanwhit

tests/test/mod.rs

@@ -307,6 +307,7 @@ mod implied_bounds;
 mod impls;
 mod misc;
 mod negation;
+mod never;
 mod object_safe;
 mod projection;
 mod refs;

tests/test/never.rs

@@ -0,0 +1,13 @@
+use super::*;
+
+#[test]
+fn never_is_well_formed() {
+    test! {
+        program { }
+        goal {
+            WellFormed(!)
+        } yields {
+            "Unique"
+        }
+    }
+}