[PATCH 7 of 7] histedit: use scmutil.cleanupnodes (BC)

[Jun Wu]

Excerpts from Martin von Zweigbergk's message of 2017-07-09 12:54:50 -0700:
> I agree that amend and metaedit should not need it. I could be made an
> option, since at least rebase and histedit seem to need it. Anyway, we
> can always deal with that when someone files a bug report.

An option sounds good to me. I'll send a follow-up once the number of my
pending patches decreases a bit.

> >
> >> > +    scmutil.cleanupnodes(repo, mapping, 'histedit')
> >> >
> >> >      state.clear()