branchmap: remove redundant sort There is absoluty no benefit in sorting a list that's being merged into a set on the next line. The changelog.ancestors() call later on also doesn't benefit from a sorted sequence of revs. Differential Revision: https://phab.mercurial-scm.org/D5111

revset: drop special case of 'revset(...)' function in analyze We now have a valid no-op function. We no longer need the special case.

revset: document the `revset(...)` syntax We introduce a new "no-op" function to bear the documentation. In practice, the parsing step is skipping it so it is not even called. This will get fixed in the next changeset.