This complements commit "fuse: allow filesystems to disable
CAP_AUTO_INVAL_DATA" and teaches go-fuse to request explicit data cache
invalidation mode if fuse.MountOptions.ExplicitDataCacheControl is set.

See https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/commit/?id=ad2ba64dd489
and https://lwn.net/ml/linux-fsdevel/20190315212556.9315-1-kirr%40nexedi.com/ for rationale and details.