Auto merge of #37456 - estebank:unused-imports-verbosity, r=jonathandturner

Group unused import warnings per import list

Given a file

``` rust
use std::collections::{BinaryHeap, BTreeMap, BTreeSet};

fn main() {}
```

Show a single warning, instead of three for each unused import:

``` nocode
warning: unused imports, #[warn(unused_imports)] on by default
 --> file2.rs:1:24
  |
1 | use std::collections::{BinaryHeap, BTreeMap, BTreeSet};
  |                        ^^^^^^^^^^  ^^^^^^^^  ^^^^^^^^
```

Include support for lints pointing at `MultilineSpan`s, instead of just
`Span`s.

Fixes #16132.

0 files changed, 0 insertions, 0 deletions