changectx: use unfiltered changelog to walk ancestors in annotate Since we are only walking ancestors, it is safe to use an unfiltered repository. (Because if the original rev is not filtered, none of its ancestors will be). Differential Revision: https://phab.mercurial-scm.org/D7501

localrepo: also fast past the parents of working copies parents There are descent odds that they will be needed too. So we also cache and fastpath them. Differential Revision: https://phab.mercurial-scm.org/D7498