[PATCH 2 of 2] revlog: reintroduce `revlog.descendant` as deprecated

[Yuya Nishihara]

On Mon, 16 Jul 2018 18:30:17 +0200, Boris Feld wrote:
> # HG changeset patch
> # User Boris Feld <boris.feld at octobus.net>
> # Date 1531750963 -7200
> #      Mon Jul 16 16:22:43 2018 +0200
> # Node ID 52aa3f0c736e48779c3f0ef4ee54545dd73576b7
> # Parent  94a6a0ef74f6e52cbb26e3461df2f155ab873039
> # EXP-Topic deprecate-descendant
> # Available At https://bitbucket.org/octobus/mercurial-devel/
> #              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 52aa3f0c736e
> revlog: reintroduce `revlog.descendant` as deprecated

> +    def descendant(self, a, b):
> +        msg = (b'revlog.descendant is deprecated, use revlog.isancestorrev')
> +        self._repo.ui.deprecwarn(msg, b'4.7')
> +        return self.isancestorrev(a, b)

This appears to be ninja queued, but wouldn't work since revlog has no
self._repo.