Add tests for undef smart-matching

diff --git a/t/op/smartmatch.t b/t/op/smartmatch.t
index 1ef56c1..86ea187 100644 (file)
--- a/t/op/smartmatch.t
+++ b/t/op/smartmatch.t
@@ -268,3 +268,5 @@ __DATA__
 !      !1              undef
 !      \&foo           undef
 !      sub { }         undef
+       undef           undef
+       $::undef        undef