upgrade: allow sidedata upgrade to modify revision flag
In the process, we fix the lack of HAS_COPIES_INFO flag on upgrade, and test the
results.
Differential Revision: https://phab.mercurial-scm.org/D9199
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}