allow example to compile

Author: coke

doc/Type/IO/Path.pod6

@@ -594,6 +594,7 @@ File tests include
 All of these tests can be used as methods (without the colon).
 Three tests, however exist only as methods:
 
+=for code :preamble<my $fh>
     $fh.modified;
     $fh.accessed;
     $fh.changed;