Invalid bound for for field type like <T>::A

[gui1117]

The following test:

trait Types {
	type A;
}
#[derive(Encode, Decode)]
struct Assoc<T: Types> {
	a: <T>::A,
}

Fails with:

error: generic parameters on `where` clauses are reserved for future use
  --> tests/foo.rs:11:5
   |
11 |     a: <T>::A,
   |        ^^^ currently unsupported

error: proc-macro derive produced unparseable tokens
 --> tests/foo.rs:9:18
  |
9 | #[derive(Encode, Decode)]
  |                  ^^^^^^

error: proc-macro derive produced unparseable tokens
 --> tests/foo.rs:9:10
  |
9 | #[derive(Encode, Decode)]
  |          ^^^^^^

error[E0412]: cannot find type `A` in the crate root
  --> tests/foo.rs:11:10
   |
11 |     a: <T>::A,
   |             ^ not found in the crate root

error[E0282]: type annotations needed
  --> tests/foo.rs:10:14
   |
10 | struct Assoc<T: Types> {
   |              ^ cannot infer type for type parameter `T`

This is probably due to a wrong expansion in some of the code in derive/src/trait_bound.rs