Hovering `Self` of an impl does not show memory layout

[Veykril]

struct Foo(i32) where Self:; // This `Self` works, as its an ADT Self type

// these two do not as they are impl self types, but we can totally calculate the layout of these 
impl Foo {
    fn f() -> Self 
		where Self: 
	{loop {}}
}

[justahero]

@rustbot claim

[ShoyuVanilla]

struct Foo(i32) where Self:; // This `Self` works, as its an ADT Self type

@Veykril This doesn't give layout hints anymore, as we only render layout hints on NameClasss, not on NameRefClasss.
Implementing this is quite simple, but should we do this?

[Veykril]

Hmm, that's annoying :D I think we still want to do this here, given we have no declaration side and Self can be an arbitrarily complex type so seeing its layout is still useful. That is in general for things that do not have a definition site we should show the extra info things imo