title: How to compare two non-sequential pull request updates in VSTS?
body: <p>In VSTS (now Azure DevOps), multiple updates can be pushed to a pull request (PR).  You can compare any update with its previous update, and you can compare a rolled-up view of all updates with the original code before any changes were made.  But how do I compare two arbitrary, non-sequential updates?</p>
  
  <p>My scenario is that a PR has had quite a bit of back-and-forth with a total of 8 updates pushed.  I last reviewed update 5, but now 3 more updates exist.  I don't want to review 6-5, 7-6, 8-7 or all updates, I just want to review 8-5.  How do I do that?</p>