rustdoc: Weird display of `<ToBytes for Simd<_, _>>::Bytes` associated type

Implementations of ToBytes for various portable SIMD vectors are rendered incorrectly:

type Bytes = Simd<u8, core::::core_simd::to_bytes::{impl#55}::Bytes::{constant#0}>

https://doc.rust-lang.org/nightly/std/simd/prelude/struct.Simd.html#impl-ToBytes-for-Simd%3Cf32,+8%3E

(looks the same on stable: https://doc.rust-lang.org/stable/std/simd/prelude/struct.Simd.html#impl-ToBytes-for-Simd%3Cf32,+8%3E)

It’s probably reproducible with some other traits and types, but I was not able to do it. Notably, this:

pub trait Foo {
    type Bar;
}

struct Arr<T, const N: usize>(T);

macro_rules! gen_impl {
    ($a:literal, [$($b:literal),*]) => {
        $(impl Foo for [u8; $b] {
            type Bar = Arr<u8, { $a * $b }>;
        })*
    };
}

gen_impl!(2, [3, 4]);

renders as

type Bar = Arr<u8, { $a * $b }>

for me (stable + rustc 1.82.0-nightly (64ebd39da 2024-08-03)), which is maybe not perfect, but isn’t that broken.

Start with the linked rustdoc pages and the ToBytes/Simd rendering example, then compare it with the supplied Foo/Arr macro case to isolate the associated-type display path. Done means the SIMD associated type renders as valid Rust without the duplicated core path or unresolved macro tokens.