DEFINE_UNION_TESTS
DEFINE_UNION_TESTS(base ## _ ## partial, \
DEFINE_UNION_TESTS(base ## _ ## all, xfail)
DEFINE_UNION_TESTS(zero, ALWAYS_PASS);
DEFINE_UNION_TESTS(old_zero, ALWAYS_PASS);
DEFINE_UNION_TESTS(assigned_copy, ALWAYS_FAIL);