With a recent upgrade to a newer version of MSVC we now get a bunch of
warnings when two operands use different enum types. While sensible in
theory, in practice we have a couple of non-public enums that extend
public enums, like for example with `GIT_SUBMODULE_STATUS`.
Let's for now disable this warning to unblock our builds. The
alternative would be to add casts all over the place, but that feels
rather cumbersome.
1b07eecf91