full diff: https://github.com/moby/buildkit/compare/v0.8.0-rc2...v0.8.0
note that this is currently a few commits "behind" the version used in docker,
but changes since v0.8.0 do not affect the code that's vendored in the CLI,
so prefering to use a tagged version.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Sebastiaan van Stijn