Cannot dump blessed globs

This is https://rt.cpan.org/Public/Bug/Display.html?id=67678 .

Known [broken since 2003](http://www.perlmonks.org/?node_id=235770).  Sorry I didn't fix it properly when I last met it (2009) and just hacked my local copy.

This fix should be enough to allow data structures to be dumped for debugging (my purpose), but I don't know about round-tripping.