Imagine somebody doing a drive-by on your repo and dropping a 270k loc PR expecting you to merge it. Bonus points if they can't even put in the 0.001% smidgen of effort to write why they think the PR is useful or necessary in their own words. Oh, but we don't have to imagine it, because there are people who actually do that!
The PR is against bun's fork of WebKit, not upstream.
The title is of this post is definitely confusing if not misleading.
Besides, the title should probably have referred to it as "a giant open PR" or something, because I don't think what the submission is trying to focus on is the feature itself.
Oh, my mistake, I thought they were doing the zig thing again.
They didn't open a PR against zig either, the compiler concurrency work they did was also only ever in their own fork.