cmdutil: make getgraphlogrevs limit-aware For a repository with over 400,000 changesets, this speeds up graphlog with a small limit by around 0.05 seconds (~50%).

cmdutil: stop pretending we can calculate revs for graphlog lazily cmdutil.getgraphlogrevs does a ton of work trying to build a graphlog lazily, and then cmdutil.graphlog comes along and destroys all of that. graphmod.dagwalker requires that it be given the full list of revs upfront so that it can perform filtering and tests against known revs. For a repository with over 400,000 changesets, this speeds up graphlog by around 0.02 seconds (~20% with a small limit).

cmdutil: store a local ref to repo.hiddenrevs in getgraphlogrevs On a repository with over 400,000 changesets, this speeds graphlog up by around 0.03 seconds (~20% with a small limit).