Skip generating an empty (broken) test case.
Skip generating an empty (broken) test case.

It's possible that all the cases in a given batch are excluded if
the offsets line up just right, which will cause the test to fail.
Don't generate an invalid test in this case.

PiperOrigin-RevId: 345276588

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor