Make VersionRange implement Comparable.

This changes the ordering of ranges in a VersionUnion. It used to order
solely by the upper bound; it now orders by lower bound, then upper
bound. In addition to being a more intuitive ordering, this is easier to
programatically work with, because iterating through the ranges reaches
each one in the order of the versions it contains.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//2035983002 .
7 files changed
tree: b493d9d1c8bc6c806450378bb108d1a8970ba276
  1. pkgs/