Return correct HirId when finding body owner in diagnostics
Fixes#129145Fixes#128810
r? ```@compiler-errors```
```rust
fn generic<const N: u32>() {}
trait Collate<const A: u32> {
type Pass;
fn collate(self) -> Self::Pass;
}
impl<const B: u32> Collate<B> for i32 {
type Pass = ();
fn collate(self) -> Self::Pass {
generic::<{ true }>()
//~^ ERROR: mismatched types
}
}
```
When type checking the `{ true }` anon const we would error with a type mismatch. This then results in diagnostics code attempting to check whether its due to a type mismatch with the return type. That logic was implemented by walking up the hir until we reached the body owner, except instead of using the `enclosing_body_owner` function it special cased various hir nodes incorrectly resulting in us walking out of the anon const and stopping at `fn collate` instead.
This then resulted in diagnostics logic inside of the anon consts `ParamEnv` attempting to do trait solving involving the `<i32 as Collate<B>>::Pass` type which ICEs because it is in the wrong environment.
I have rewritten this function to just walk up until it hits the `enclosing_body_owner` and made some other changes since I found this pretty hard to read/understand. Hopefully it's easier to understand now, it also makes it more obvious that this is not implemented in a very principled way and is definitely missing cases :)
ddbbda47eb