merge: introduce mergeresult.updateactions() and use it
We don't want direct editing and access of mergeresult._actions because soon we
will like to maintain data in other structures also.
Differential Revision: https://phab.mercurial-scm.org/D8826
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}