Just so we're completely clear, Google has been an incredibly long-term contributor to basically all parts of LLVM. So have sooooo many other companies. This is a really cool project IMO, but it doesn't represent a significant change in who or how much anyone is contributing to LLVM... It's a drop in the bucket.

And for the record, LLVM is doing fine with all these corporate contributors.

I'm not trying to say that this can't be a concern for OSS communities and projects, but LLVM seems to have a quite successful and sustainable model here.