flagutil: introduce a flagprocessorsmixin class
To avoid code duplication, we will provide a simple "ready to use" mixin that
carry the appropriate logic. First we use it in standard revlog, we'll remove
code duplication in later changesets.
Differential Revision: https://phab.mercurial-scm.org/D6796
[workspace]
members = ["hg-core", "hg-direct-ffi", "hg-cpython"]
exclude = ["chg", "hgcli"]