Rollup merge of #112729 - jieyouxu:unused-qualifications-suggestion, r=b-naber

Add machine-applicable suggestion for `unused_qualifications` lint

```
error: unnecessary qualification
  --> $DIR/unused-qualifications-suggestion.rs:17:5
   |
LL |     foo::bar();
   |     ^^^^^^^^
   |
note: the lint level is defined here
  --> $DIR/unused-qualifications-suggestion.rs:3:9
   |
LL | #![deny(unused_qualifications)]
   |         ^^^^^^^^^^^^^^^^^^^^^
help: replace it with the unqualified path
   |
LL |     bar();
   |     ~~~
```

Closes #92198.

compiler/rustc_lint/src/context.rs

@@ -956,6 +956,14 @@ pub trait LintContext: Sized {
                     db.span_note(glob_reexport_span, format!("the name `{}` in the {} namespace is supposed to be publicly re-exported here", name, namespace));
                     db.span_note(private_item_span, "but the private item here shadows it".to_owned());
                 }
+                BuiltinLintDiagnostics::UnusedQualifications { path_span, unqualified_path } => {
+                    db.span_suggestion_verbose(
+                        path_span,
+                        "replace it with the unqualified path",
+                        unqualified_path,
+                        Applicability::MachineApplicable
+                    );
+                }
             }
             // Rewrap `db`, and pass control to the user.
             decorate(db)