RFC: Using VCS snapshots

Despite the best of our ability, sometimes pregenerated files manage to slip through the cracks, such as with coreutils 5.0 today, there's been a couple other cases too.

Perhaps it would be a better idea to source all of our distfiles from VCS (normally git) snapshots?

Git snapshots are less likely to have pregenerated files generally speaking. They will obviously still have some in some cases, but there is less margin for manual auditing error not finding pregenerated files.

Thoughts?