Rollup of 6 pull requests

[frewsxcv]

• Successful merges: transition borrowck to visit all **bodies** and not item-likes #39927, rustbuild: use deterministic step ordering and respect path order on the command-line. #40152, add unstable book to the bookshelf #40154, Reduce std_unicode’s public API #40189, rustbuild: Build documentation for proc_macro #40199, LLVM: Update submodule to include x86-interrupt ABI patches #40207
• Failed merges:

[frewsxcv]

@bors r+ p=10

[bors]

📌 Commit 88dfa20 has been approved by frewsxcv

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @nikomatsakis (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

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[bors]

⌛ Testing commit 88dfa20 with merge 89cf5d3...

[bors]

💔 Test failed - status-travis

[bors]

☔ The latest upstream changes (presumably #40178) made this pull request unmergeable. Please resolve the merge conflicts.