redundant_clone: Migrate to new dataflow framework
Migration to [the new dataflow framework](https://github.com/rust-lang/rust/pull/65672) is ongoing in rustc. This PR updates the dataflow impl in `redundant_clone` lint.
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changelog: none
I like to move it, move it
GHA now runs in the background for 6 days (#5088)
Since then ~~15~~ 19 PRs were successfully merged and Travis+Appveyor agreed on the status in every case. ([GitHub PR search query](https://github.com/rust-lang/rust-clippy/pulls?utf8=%E2%9C%93&q=is%3Apr+is%3Amerged+merged%3A%3E%3D2020-02-12T15%3A42%3A00+sort%3Aupdated-desc+NOT+%5Bgh-pages%5D+in%3Atitle))
Some PRs were:
- #5163
- #5170
- #5168
- #5173
- #5171
- #5156
- #4809
- #5177
- #5182
- #5183
- #5184
- #5185
- #5186
- #5181
- #5189
Bug with GHA:
- When a rustc PR gets merged between the `integration_build` and the `integration` job, the `integration` job will fail. This happened once in #5162, but not in the past 6 days. Even if it would happen every 4th PR we would save time, since splitting up the integration build and tests saves 5-7 minutes per run and a complete run takes 15-17 minutes
- Sometimes the MacOS build takes up to an hour to download the master toolchain. Until now, this happend 2 or 3 times and can be resolved by a `@bors r3try`+canceling the previous run (restarting single jobs is not supported yet)
## Before merging this, https://github.com/rust-lang/rust-central-station/pull/578 has to get merged
This PR is for starting the discussion and to get consensus (@rust-lang/clippy) on a final move to GHA. If we're ready, I'll contact Pietro, to finalize the move.
changelog: Clippy completely runs on GHA now 🎉
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BTW: The deployment already runs on GHA, instead of Travis.
Expand `missing_errors_doc` to also work on async functions
This adds the `missing_errors_doc` lint to async functions.
changelog: Make [`missing_errors_doc`] lint also trigger on `async` functions
Improve deployment and documentation
**This should be merged shortly after** #5172
This extracts the python code that generated the `versions.json` file and now sorts the versions. in addition to that it improves the order on the website, respecting the new `rust-*` directories.
The new appearance of the documentation site can be previewed here: https://flip1995.github.io/rust-clippy/
changelog: Add documentation for Clippy stable releases at https://rust-lang.github.io/rust-clippy/
