Wrong error message shown when a `_` is used in place of generic constant

[InnocentusLime]

Given the following code:

static TEST : [i32; _] = [1i32, 2i32];
fn main() {}

The current output is:

error[E0658]: destructuring assignments are unstable
 --> src/main.rs:1:21
  |
1 | static TEST : [i32; _] = [1i32, 2i32];
  |                     ^
  |
  = note: see issue #71126 <https://github.com/rust-lang/rust/issues/71126> for more information

Ideally the output should look like:

error[E0747]: type provided when a constant was expected
 --> src/main.rs:3:16
  |
1 | static TEST : [i32; _] = [1i32, 2i32];
  |                     ^
  |
  = help: const arguments cannot yet be inferred with `_`

The sample code doesn't seem to be related to the destructuring assignment feature nonetheless.

This, although quite artificial looking, use case too causes the wrong looking output

fn test() -> [i32; _] { [2, 1] }
fn main() {}

Output:

error[E0658]: destructuring assignments are unstable
 --> src/main.rs:3:20
  |
3 | fn test() -> [i32; _] { [2, 1] }
  |                    ^
  |
  = note: see issue #71126 <https://github.com/rust-lang/rust/issues/71126> for more information
  = help: add `#![feature(destructuring_assignment)]` to the crate attributes to enable

error: in expressions, `_` can only be used on the left-hand side of an assignment
 --> src/main.rs:3:20
  |
3 | fn test() -> [i32; _] { [2, 1] }
  |                    ^ `_` not allowed here

Some code seems to print correct the error messages (kinda?):

struct T<const U : usize>([i32; U]);
fn test() -> T<_> { T([2, 1]) }
fn main() {}

Output

error[E0747]: type provided when a constant was expected
 --> src/main.rs:3:16
  |
3 | fn test() -> T<_> { T([2, 1]) }
  |                ^
  |
  = help: const arguments cannot yet be inferred with `_`

error[E0121]: the type placeholder `_` is not allowed within types on item signatures
 --> src/main.rs:3:16
  |
3 | fn test() -> T<_> { T([2, 1]) }
  |                ^ not allowed in type signatures

Meta

This happens on stable, beta and nightly.

[BoxyUwU]

the following code is the same issue I believe:

fn main() {
  let foo: [_; _] = [];
}