Pierre-Yves David <pierre-yves.david@fb.com> [Tue, 07 Oct 2014 00:12:56 -0700] rev 22803
mq: use `revs.sort()` to ensure the set is ascending
Sorting is super-cheap with the new smartset class, so we can use it to enforce
the order. Otherwise all smartset classes would have to allow direct indexing.