James,
In r16751, certain code was repositioned to conform with Parrot coding standards. However, when repositioning code in test files, one is well advised to re-run the tests to see if they all still pass. This apparently was not done. If they had been done, it would have been evident that calling 'use strict' before the BEGIN block -- with no other changes -- was ill advised.
I did rereun the tests otherwise I wouldn't have done the commit. However, as you mention, make test is insufficient. I will broaden the tests I run now, and this won't happen again. I apologise (again) for the coding standards changes getting in people's way. Paul