never_type: test interaction with auto traits

src/test/ui/never_type/auto-traits.rs

@@ -0,0 +1,16 @@
+// check-pass
+
+#![feature(optin_builtin_traits)]
+
+fn main() {
+    enum Void {}
+
+    auto trait Auto {}
+    fn assert_auto<T: Auto>() {}
+    assert_auto::<Void>();
+    assert_auto::<!>();
+
+    fn assert_send<T: Send>() {}
+    assert_send::<Void>();
+    assert_send::<!>();
+}