[llvm-dev] [RFC] One or many git repositories?

[Robinson, Paul via llvm-dev]

> The only thing a monorepo gets you that strictly isn’t possible without
> it is the ability to commit to multiple projects in a single commit.
> Personally I don’t think that is a big enough justification, but that is
> my opinion, not a fact.

Okay, I just bumped into r277008, in which commits to llvm, clang, and
clang-tools-extra all have the same SVN revision number.
I don't know how it happened but it did.  Is this just an artifact of
how somebody pasted together a bunch of git-svn projects, or is it
something that a top-level git repo with submodules would allow?
And if it is, then the "only thing a monorepo gets you" isn't something
that you need a monorepo to get.
Your befuddled correspondent,
--paulr