localrepo: clear _filecache on rollback (issue3261)
Files are being replaced by rollback but the corresponding data in localrepo
isn't actually updated for things like bookmarks, phases, etc. Then when
rollback is done, the cache is updated thinking it has the most up-to-date
data, where in fact it is still pre-rollback.
We clear _filecache to force everything to be recreated.
$ "$TESTDIR/hghave" pyflakes || exit 80
$ cd `dirname $TESTDIR`
$ pyflakes mercurial hgext 2>&1 | $TESTDIR/filterpyflakes.py
hgext/inotify/linux/__init__.py:*: 'from _inotify import *' used; unable to detect undefined names (glob)