Update Changelog
I also changed the formatting of the changelog for the beta changelog. I can also do this for all the previous releases, if this formatting gets accepted.
[Rendered](https://github.com/flip1995/rust-clippy/blob/changelog/CHANGELOG.md)
r? @Manishearth
changelog: none
Extend `redundant_clone` to the case that cloned value is not consumed
Fixes#5303.
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changelog: Extend `redundant_clone` to the case that cloned value is not consumed
add lint on File::read_to_string and File::read_to_end
Adds lint `verbose_file_reads` which checks for use of File::read_to_end and File::read_to_string.
Closes https://github.com/rust-lang/rust-clippy/issues/4916
changelog: add lint on File::{read_to_end, read_to_string}
Use `edition:2018` flag more widely
Now we recommend using `// edition:2018`, so let's use it more widely.
Also replace a too old example with new one in the docs.
changelog: none
Update rustc-guide to rustc-dev-guide
The rustc-guide is being renamed to the rustc-dev-guide. The discussion is in rust-lang/rustc-guide#470.
This PR revises rustc-guide to rustc-dev-guide in the Readme Markdown file.
Transition tracker: rust-lang/rustc-guide#602
changelog: none
Improve placeholder in map_unit_fn
Instead of using `_` as a default placeholder use `a`.
fixes#5180
changelog: Improve default placeholder in map_unit_fn
redundant_pattern: take binding (ref, ref mut) into account in suggestion
fixes#5271
changelog: redundant_pattern: take binding (ref, ref mut) into account in suggestion (#5271)
Fix match single binding when in a let stmt
Fix bad suggestion when `match_single_binding` lints when inside a local (let) statement.
Fixes#5267
changelog: none
Improve error messages for {option,result}_map_unit_fn
Instead of saying "unit function", use the phrase the description uses: "function that returns the unit type".
Fixes#5180.
changelog: Improve error messages for {option,result}_map_unit_fn
Mention the setup instructions in CONTRIBUTING
Multiple people seem to have missed this based on questions asked in the Discord channel. Might as well mention it up front.
changelog: none
