Clippy suggests incorrect fix

[he-thinks]

Summary

Clippy suggests incorrect fixes for #[warn(unused_parens)] for these patterns (the same issue with the stable 1.73.0 rustc):

let(mut _x): i8 = 0;
let( mut _x): i8 = 0;
let(_x): i8 = 0;

Reproducer

I tried this code:

fn main() {
    let(mut _x): i8 = 0;
}

I expected to see this happen:

warning: unnecessary parentheses around pattern
 --> src/main.rs:2:8
  |
2 |     let(mut _x): i8 = 0;
  |        ^      ^
  |
  = note: `#[warn(unused_parens)]` on by default
help: remove these parentheses
  |
2 -     let(mut _x): i8 = 0;
2 +     let mut _x: i8 = 0;
  |

Instead, this happened:

warning: unnecessary parentheses around pattern
 --> src/main.rs:2:8
  |
2 |     let(mut _x): i8 = 0;
  |        ^      ^
  |
  = note: `#[warn(unused_parens)]` on by default
help: remove these parentheses
  |
2 -     let(mut _x): i8 = 0;
2 +     letmut _x: i8 = 0;
  |

Version

rustc 1.75.0-nightly (e5cfc5547 2023-10-28)
binary: rustc
commit-hash: e5cfc55477eceed1317a02189fdf77a4a98f2124
commit-date: 2023-10-28
host: x86_64-pc-windows-gnu
release: 1.75.0-nightly
LLVM version: 17.0.3

Additional Labels

No response

[y21]

Shouldn't this be on the rust-lang/rust repo? unused_parens is a rustc lint, not a clippy lint.

[he-thinks]

Shouldn't this be on the rust-lang/rust repo? unused_parens is a rustc lint, not a clippy lint.

Thanks, I reopened this issue in the rust-lang/rust repo. #117380