When encountering a name in an import that could have come from a crate that wasn't imported, use a structured suggestion to suggest `extern crate foo;` pointing at the right place in the crate.
When encountering `_` in an import, do not suggest `extern crate _;`.
```
error[E0432]: unresolved import `spam`
--> $DIR/import-from-missing-star-3.rs:2:9
|
LL | use spam::*;
| ^^^^ maybe a missing crate `spam`?
|
help: consider importing the `spam` crate
|
LL + extern crate spam;
|
```
We don't want to have questions in the diagnostic output. Instead, we use wording that communicates uncertainty, like "might":
```
error[E0432]: unresolved import `spam`
--> $DIR/import-from-missing-star-3.rs:2:9
|
LL | use spam::*;
| ^^^^ you might be missing crate `spam`
|
= help: consider adding `extern crate spam` to use the `spam` crate
```
