Rollup merge of #122591 - gurry:122162-impl-type-binding-suggestion, r=fmease

Suggest using type args directly instead of equality constraint

When type arguments are written erroneously using an equality constraint we suggest specifying them directly without the equality constraint.

Fixes #122162

Changes the diagnostic in the issue from:
```rust
error[E0229]: associated type bindings are not allowed here
9 | impl std::cmp::PartialEq<Rhs = T> for S {
  |                          ^^^^^^^ associated type not allowed here
  |
```
to
```rust
error[E0229]: associated type bindings are not allowed here
9 | impl std::cmp::PartialEq<Rhs = T> for S {
  |                          ^^^^^^^ associated type not allowed here
  |
help: to use `T` as a generic argument specify it directly
  |
  |      impl std::cmp::PartialEq<T> for S {
  |                               ~
```

0 files changed, 0 insertions, 0 deletions