faefc618cf
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.
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.