single_match incorrectly lints on exhaustive matches inside of Option/Result

[awused]

Summary

single_match isn't supposed to lint on exhaustive matches of user-defined types, but it will if those are inside an Option or Result.

Lint Name

single_match

Reproducer

I tried this code:

enum Test {
    A,
    B,
}

fn main() {
    let test = Some(Test::A);

    match test {
        Some(Test::A | Test::B) => todo!(),
        None => {}
    }
}

Clippy suggests this code:

    if let Some(Test::A | Test::B) = test {
        todo!()
    }

I expected to see this happen:

Nothing, single_match should not trigger here since I've exhaustively listed every variant of my enum. It seems some specific carve-outs were added for Option/Result in single_match, but they're over-eager. The code clippy suggests is equivalent, right now, but if I were to add a Test::C variant without remembering to handle it, clippy's version would not catch it.

Version

rustc 1.71.1 (eb26296b5 2023-08-03)
binary: rustc
commit-hash: eb26296b556cef10fb713a38f3d16b9886080f26
commit-date: 2023-08-03
host: x86_64-unknown-linux-gnu
release: 1.71.1
LLVM version: 16.0.5

Additional Labels

No response