Fixes clippy toolstate
Changes:
````
Match on ast/hir::ExprKind::Err
Update *.stderr files
Use -Zui-testing flag
Mention S-inactive-closed PRs in the CONTRIBUTING.md
tests: fix formatting and update test output
base tests: make sure to fail CI if tests need formatting
base tests: switch to nightly toolchain before checking formatting of tests with rustfmt
rustup https://github.com/rust-lang/rust/pull/57069
Rustfmt.
fix breakage from rust-lang/rust#57088
fix a couple of ftrivial typos (NFC).
update CARGO_CLIPPY_HELP string to suggest tool lints.
rustc_tools_util: add readme
rustc_tool_utils: expand Cargo.toml with a few keywords in preparation for crates.io release
Fix macro detection in `empty_loop`.
Changed `macro_backtrace()` to `in_macro()`.
Fix lint detection on macro expansion.
````
1654ef8fa3