The test bucket_unpacking_with_sort_extended_range.js recently stopped being run in any of the balancer suites, because it uses getMore() which can cause spurious stale cursor errors. This looks to be our only test that covers sorting time series collections with extended range values.

However, it would be good to get this test coverage back as it has caught a BF, even though I couldn't reproduce it.

We should add a sharding test that manually moves chunks and show that we correctly set the extended range bit and do or do not use bounded sort accordingly.