rustdoc incorrectly prints APIT in `AliasTy::new`

[lcnr]

https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/type.AliasTy.html#method.new

currently prints the method signature as

pub fn new(
    interner: I,
    def_id: <I as Interner>::DefId,
    args: impl IntoIterator>,
) -> AliasTy<I>
where
    <impl IntoIterator as IntoIterator>::Item: Into<<I as Interner>::GenericArg>,

I cannot reproduce this outside of the nightly compiler docs.

[fmease]

Issue with inlined cross-crate re-exports (middle::ty cleaning as opposed to HIR cleaning). IXCRE ATBs haven't been impl'ed yet (cc #126432). Example MCVE:

a.rs (rustc --crate-type lib):

pub fn f(_: impl Iterator<Item: Copy>) {}

b.rs (rustdoc b.rs --edition 2018 -L. --extern a):

pub use a::*;

Rendered:

pub fn f(_: impl Iterator)
where
    <impl Iterator as Iterator>::Item: Copy,