storage/spanset: clarify and clean up "reversed" span checks#45085

Merged

craig[bot] merged 2 commits intocockroachdb:masterfrom nvanbenschoten:nvanbenschoten/spanRevCheck

Feb 14, 2020

+232-155

Commits on Feb 13, 2020

storage: clean up TestSpanSetBatchBoundaries and test exclusive upper bound
nvanbenschoten
committed
storage/spanset: clarify and clean up "reversed" span checks
nvanbenschoten
committed