There were two cases where tests in intl402/ had some duplication of tests
that are in built-ins/ as well. Remove this duplication, and restrict the
intl402/ tests to testing things that can't be tested on all hosts.
For cases in the previous commit that actually removed some functionality
from tests in built-ins/, add corresponding tests in intl402/ to preserve
test coverage of that functionality for hosts that do support Intl.