Changes:
````
Rustup to rust-lang/rust#69674
Use visit_place
Check for mutation
Only fires on temporaries
Extend `redundant_clone` to the case that cloned value is not consumed
add CR feedback
Improve documentation
Use `edition:2018` flag more widely
Update tests/ui/needless_doc_main.rs
Move links to the end of each chapter on adding_lints
Move links to the end of each chapter on CONTRIBUTING
Clean-up adding_lints.md
Clean-up CONTRIBUTING.md
needless_doc_main: only check rust code
Use `node_type_opt` over `node_type`
Fix doc
Fix ICE with trivial_bounds feature
clippy_lints: readme: don't mention crates.io since it is no longer used to publish clippy.
update rust-lang.github.io to rustc-dev-guide.rust-lang.org
Improve placeholder in map_unit_fn
Fix match single binding when in a let stmt
Improve error messages for {option,result}_map_unit_fn
Mention the setup instructions in CONTRIBUTING
redundant_pattern: take binding (ref, ref mut) into account in suggestion.
check_pat: delay creation of the "normal" vec until we reach the branch where is is actually needed
deps: bump itertools 0.8 -> 0.9
add lint on File::read_to_string and File::read_to_end
transition rustc-guide to rustc-dev-guide
Rename macro_use_import -> macro_use_imports
warn on macro_use attr
Fix deploy script for tag deploys
````
Fixes#69957
Polonius: update `polonius-engine` to 0.12.0
Since @albins won't have the time to finish up #68993 for a while, I'll take care of the trivial remaining tasks (rebasing, taking care of tidy/rustfmt).
I'll r? @nikomatsakis since they're assigned to #68993, but have actually [already reviewed it pre-rebase](https://github.com/rust-lang/rust/pull/68993#issuecomment-586413089).
When CI passes: I'll notify bors and close#68993, since this PR supersedes it.
Remove experimental chalk option
As suggested by @nikomatsakis [here](https://github.com/rust-lang/rust/pull/68807#issuecomment-583339932).
The current version of chalk used by the experimental `-Zchalk` flag is [v0.9.0, which is over a year old](https://crates.io/crates/chalk-engine). Since v0.9.0, chalk has seen [a lot of further development](https://github.com/rust-lang/chalk/compare/41dfe13...master), and the intent is to eventually upgrade rustc to use a more recent chalk.
However, it will take a decent chunk of effort to upgrade the current experimental chalk support, and it is currently [blocking at least some PRs](https://github.com/rust-lang/rust/pull/68807) due to chalk:0.9.0's use of unstable features. So for the interim until the next chalk release and experimental rustc integration, we remove the chalk-specific code from rustc.
[experiment] Support linking from a .rlink file
Flag `-Z no-link` was previously introduced, which allows creating an `.rlink` file to perform compilation without linking. This change enables linking from an `.rlink` file.
Part of Issue #64191
Flag `-Z no-link` was previously introduced, which allows creating
an `.rlink` file to perform compilation without linking.
This change enables linking from an `.rlink` file.
Changes:
````
Update jobserver.
Update tar.
Emit report on error with Ztimings.
Do not run `formats_source` if `rustfmt` is not available
Fix rebuild_sub_package_then_while_package on HFS.
Remove likely brittle test.
Install rustfmt for testing in CI
Fix build-std collisions.
Fix BuildScriptOutput when a build script is run multiple times.
Fix required-features using renamed dependencies.
Fix using global options before an alias.
Update changelog for 1.42.
Bump to 0.44.0.
Log rustfmt output if it fails; also do not check that rustfmt exists
Update pretty_env_logger requirement from 0.3 to 0.4
Swap std::sync::mpsc channel with crossbeam_channel
Fix tests on Linux/MacOS
Fix typo.
Add tests
Deduplicate warnings about missing rustfmt
Log entry 2: first implementation
Refactor code
Stabilize config-profile.
Log entry 1
Format code
Remove tempdir after install
Keep existing package with git install
Use non-ephemeral workspace
Test that git install reads virtual manifest
Fix failing test
Search for root manifest with ephemeral workspaces
Support out-dir in build section of Cargo configuration file
````
Update cargo, books
## cargo
9 commits in ad3dbe10e1e654fb1f032a5dd9481d7cbaa00d65..f6449ba236db31995255ac5e4cad4ab88296a7c6
2020-01-13 21:37:15 +0000 to 2020-01-21 16:15:39 +0000
- Fix wrong directories in host_libdir. (rust-lang/cargo#7798)
- Update humantime requirement from 1.2.0 to 2.0.0 (rust-lang/cargo#7815)
- Fix doc_target test which no longer works on stable/beta. (rust-lang/cargo#7817)
- Fix some erroneous em-dashes in man pages. (rust-lang/cargo#7814)
- fix some clippy warnings (rust-lang/cargo#7808)
- Don't assume iowait always increases on Linux (rust-lang/cargo#7803)
- Add and update some doc comments. (rust-lang/cargo#7800)
- Consistently use em-dash in environment documentation page. (rust-lang/cargo#7799)
- Load credentials only when needed (rust-lang/cargo#7774)
## reference
3 commits in e1157538e86d83df0cf95d5e33bd943f80d0248f..11e893fc1357bc688418ddf1087c2b7aa25d154d
2019-12-22 13:13:14 +0100 to 2020-01-18 21:24:08 +0100
- Small improvements to types/pointer.md (rust-lang-nursery/reference#726)
- repr(transparent): mention align=1 requirement (rust-lang-nursery/reference#737)
- Elaborate on how to use an extern static correctly (rust-lang-nursery/reference#736)
## book
4 commits in 5c5cfd2e94cd42632798d9bd3d1116133e128ac9..87dd6843678575f8dda962f239d14ef4be14b352
2019-12-16 09:27:21 -0600 to 2020-01-20 15:20:40 -0500
- Fix listing numbers (rust-lang/book#2227)
- Move `async` and `await` keywords to 'Currently in Use' (rust-lang/book#2140)
- More cleanup - remove unneeded files (rust-lang/book#2213)
- Small cleanups extracted from the bigger pr i'm working on (rust-lang/book#2212)
## rust-by-example
1 commits in 1d59403cb5269c190cc52a95584ecc280345495a..1c2bd024d13f8011307e13386cf1fea2180352b5
2019-12-27 08:27:05 -0300 to 2020-01-20 12:18:36 -0300
- CamelCase -> UpperCamelCase (rust-lang/rust-by-example#1302)
## embedded-book
1 commits in 9493b7d4dc97eda439bd8780f05ad7b234cd1cd7..4d78994915af1bde9a95c04a8c27d8dca066232a
2019-12-27 20:05:00 +0000 to 2020-01-14 08:25:25 +0000
- Update .gitattributes (rust-embedded/book#221)
