`Foo::bar()` invokes do not give suggestions for `Foo` when it is not in scope

[nikomatsakis]

In this example:

fn main() {
    let _: HashMap<u32, u32> = HashMap::new();
}

there are two uses of HashMap. Neither is in scope, but only the type gives me a suggestion for how to import it:

error[E0433]: failed to resolve. Use of undeclared type or module `HashMap`
 --> src/main.rs:2:32
  |
2 |     let _: HashMap<u32, u32> = HashMap::new();
  |                                ^^^^^^^ Use of undeclared type or module `HashMap`

error[E0412]: cannot find type `HashMap` in this scope
 --> src/main.rs:2:12
  |
2 |     let _: HashMap<u32, u32> = HashMap::new();
  |            ^^^^^^^ not found in this scope
help: possible candidates are found in other modules, you can import them into scope
  |
1 | use std::collections::HashMap;
  |
1 | use std::collections::hash_map::HashMap;
  |

This issue has been assigned to @Patryk27 via this comment.

[estebank]

Maybe, once the current ticket is resolved, we should also elide suggestions to only appear once the first time they're needed.

[estebank]

Triage: no change.

[Patryk27]

@rustbot claim