revlog: make clearcaches() more effective
clearcaches() was added several years ago in
e8d37b78acfb as part
of implementing a perf command. Since revlog instances have many caches
and since the spirit of this mostly unused method is to facilitate
performance testing, I think it's appropriate for all the revlog's
caches to get cleared when it is called.
[hgk]
path = /usr/share/mercurial/hgk