Be more lax in `.into_iter()` suggestion when encountering `Iterator` methods on non-`Iterator`

```
error[E0599]: no method named `map` found for struct `Vec<bool>` in the current scope
  --> $DIR/vec-on-unimplemented.rs:3:23
   |
LL |     vec![true, false].map(|v| !v).collect::<Vec<_>>();
   |                       ^^^ `Vec<bool>` is not an iterator
   |
help: call `.into_iter()` first
   |
LL |     vec![true, false].into_iter().map(|v| !v).collect::<Vec<_>>();
   |                       ++++++++++++
```

We used to provide some help through `rustc_on_unimplemented` on non-`impl Trait` and non-type-params, but this lets us get rid of some otherwise unnecessary conditions in the annotation on `Iterator`.

0 files changed, 0 insertions, 0 deletions