Provide structured suggestion for `#![feature(foo)]`

```
error: `S2<'_>` is forbidden as the type of a const generic parameter
  --> $DIR/lifetime-in-const-param.rs:5:23
   |
LL | struct S<'a, const N: S2>(&'a ());
   |                       ^^
   |
   = note: the only supported types are integers, `bool` and `char`
help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
   |
LL + #![feature(adt_const_params)]
   |
```

Fix #55941.

1 files changed, 5 insertions, 10 deletions

diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index 30a65d69c4e..8080216a252 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -155,16 +155,11 @@ impl<'tcx> CheckConstVisitor<'tcx> {
                 //
                 // FIXME(ecstaticmorse): Maybe this could be incorporated into `feature_err`? This
                 // is a pretty narrow case, however.
-                if tcx.sess.is_nightly_build() {
-                    for gate in missing_secondary {
-                        // FIXME: make this translatable
-                        #[allow(rustc::diagnostic_outside_of_impl)]
-                        #[allow(rustc::untranslatable_diagnostic)]
-                        err.help(format!(
-                            "add `#![feature({gate})]` to the crate attributes to enable"
-                        ));
-                    }
-                }
+                tcx.disabled_nightly_features(
+                    &mut err,
+                    def_id.map(|id| tcx.local_def_id_to_hir_id(id)),
+                    missing_secondary.into_iter().map(|gate| (String::new(), *gate)),
+                );
 
                 err.emit();
             }