upgrade: explicitly warn when a `--no-xxx` flag is overwritten
Some format upgrade/downgrades -needs- revlog to be recomputed. So we now
detect that individually and warn when it contradict explicitly passed flag.
This is part of a larger series to make `debugupgraderepo` smarter about which
revlog it picks by default.
Differential Revision: https://phab.mercurial-scm.org/D11869
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ hg qsave
$ hg qrestore 2
restoring status: hg patches saved state