In r27351 I've added code to PCT to check for non-existent subs and throw an exception at the point of the call. So, the problem is "solved" for PCT-based languages, at least.
It still doesn't help with the case of non-existent sub names in PIR, though, for which I recommend something along the lines of the patch described by chromatic in http://groups.google.com/group/perl.perl6.internals/msg/73433bac364e0bd0 . When/if that patch is implemented we can remove the duplicate code out of PCT. Pm
