Rollup of 11 pull requests

[frewsxcv]

• Successful merges: book: don’t use GNU extensions in the example unnecessarily #39775, Allow more Cell methods for non-Copy types #39793, Show five traits implementation in help when there are exactly five #39804, travis: Disable source tarballs on most builders #39824, static recursion test added to compile-fail test suite #39834, rustc: Link statically to the MSVCRT #39837, make doc consistent with var name #39839, Update procedural-macros.md #39840, Vec, LinkedList, VecDeque, String, and Option NatVis visualizations #39843, sys/mod doc update and mod import order adjust #39844, Fix typo #39846
• Failed merges:

[frewsxcv]

@bors r+ p=10

[bors]

📌 Commit e7a68c9 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 Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed.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 e7a68c9 with merge b942cd4...

[bors]

💔 Test failed - status-travis