Suggest appropriate place for type argument after associated type

[estebank]

Like we do for lifetimes, suggest the appropriate place for type arguments written after associated an type.

Given

trait Trait<T> { type Item; }
pub fn test<W, I: Trait<Item=(), W> >() {}
fn main() { }

we currently emit

error: type parameters must be declared prior to associated type bindings
  --> $DIR/issue-32214.rs:5:34
   |
LL | pub fn test<W, I: Trait<Item=(), W> >() {}
   |                                  ^

[davidtwco]

Re-opening as this was regressed by #58191 (11874a0).

[estebank]

Why wasn't that regression caught by our tests?

[davidtwco]

Why wasn't that regression caught by our tests?

The test was also updated. Presumably it wasn't noticed and the test got --bless'd.

[IFcoltransG]

The above code now generates a suggestion.

help: move the constraint after the generic argument
  |
2 | pub fn test<W, I: Trait<W, Item = ()> >() {}
  |                        ~~~~~~~~~~~~~~

I assume this issue can be closed.