Run autopkgtest checks when testing Perl transitions
We have lots of autopkgtest checks that might regress due to things that aren't spotted in rebuild testing. I'm particularly thinking of new warnings-on-use things that the pkg-perl-autopkgtest use.t check tests for.
Se it would be nice to run autopkgtest against the (whole?) archive with a new Perl, and then check whether failures occur on sid.
This is somewhat blocked on getting more disk space on perl.debian.net (#5) but some infrastructure could certainly be built before that.