This is really a test to check out support for this change. If a Perl 6
implementation is using a Test.pm that is not supporting isa-ok, then this
will cause a lot of breakage. OTOH, it *is* dogfooding, so I think it is
This has far reaching consequences for roast, and this
patch only catches a subset of them.
It also removes a few evals that were only there for error
catching, and are now useless.
Some fudging has also changed.