rebase: sort roots by revision
Previously we were sorting them by whatever implicit sort order we got
between changectx instances. Sorting by rev at least makes some sense,
so I chose that.
Differential Revision: https://phab.mercurial-scm.org/D2301
#require clang-format test-repo
$ . "$TESTDIR/helpers-testrepo.sh"
$ cd "$TESTDIR"/..
$ for f in `testrepohg files 'set:(**.c or **.cc or **.h) and not "listfile:contrib/clang-format-blacklist"'` ; do
> clang-format --style file $f > $f.formatted
> cmp $f $f.formatted || diff -u $f $f.formatted
> rm $f.formatted
> done