librank: add command line argument for cached or non-cached pages

Add -c and -C command line arguments to only count pages that are
cached (backed by storage) or non-cached (backed by ram or swap)
respectively.  Non-cached pages include all anonymous pages, as
well as file backed pages that are mapped private and then modified.

Change-Id: I95025d52f1c876b9c41fcbddaef5e95e32ebf307
1 file changed