[pugs] tests for $?LINE and $?FILE

[Garrett Rooney]

We don't have any tests for the $?LINE and $?FILE variables, although 
they do work just fine as far as I can tell.

Here's a diff adding some in a new t/magical/vars.t file, since Autrijus 
thought they should go in t/magical, but there doesn't appear to be a 
good home for them there yet.

-garrett
Index: t/magicals/vars.t
===================================================================
--- t/magicals/vars.t   (revision 0)
+++ t/magicals/vars.t   (revision 0)
@@ -0,0 +1,10 @@
+#!/usr/bin/pugs
+
+use v6;
+
+require Test;
+
+plan 2;
+
+is($?LINE, 9, '$?LINE works');
+is($?FILE, 't/magicals/vars.t', '$?FILE works');