Auto merge of #124219 - gurry:122989-ice-unexpected-anon-const, r=compiler-errors

Do not ICE on `AnonConst`s in `diagnostic_hir_wf_check`

Fixes #122989

Below is the snippet from #122989 that ICEs:
```rust
trait Traitor<const N: N<2> = 1, const N: N<2> = N> {
    fn N(&N) -> N<2> {
        M
    }
}

trait N<const N: Traitor<2> = 12> {}
```

The `AnonConst` that triggers the ICE is the `2` in the param `const N: N<2> = 1`. The currently existing code in `diagnostic_hir_wf_check` deals only with `AnonConst`s that are default values of some param, but  the `2` is not a default value. It is just an `AnonConst` HIR node inside a `TraitRef` HIR node corresponding to `N<2>`. Therefore the existing code cannot handle it and this PR ensures that it does.

Author: bors