TAIT: "hidden type captures lifetime" even if it's static, inside closure

[Dirbaio]

    let x: &'static u32 = &0;
    let _closure = move || {
        type T = impl Sized;
        let x: T = x;
    };

This code fails to compile playground with:

error[[E0700]](https://doc.rust-lang.org/nightly/error-index.html#E0700): hidden type for `T` captures lifetime that does not appear in bounds
 --> src/lib.rs:7:20
  |
7 |         let x: T = x;
  |                    ^
  |
  = note: hidden type `&u32` captures lifetime '_#8r

even though x is 'static, so it shouldn't require adding any lifetime to T's bounds.

If you move x inside the closure then it works:

    let _closure = move || {
        let x: &'static u32 = &0;
        type T = impl Sized;
        let x: T = x;
    };

Seems like x having to go through the closure captures makes TAIT not able to use the staticness of it somehow.

Nightly version: 1.67.0-nightly (2022-12-04 53e4b9d)
@rustbot label F-type_alias_impl_trait