Elaborate lint explanation

Jules-Bertholet · Jules-Bertholet · commit 4cc2f952e41a · 2025-12-06T13:48:59.000-05:00
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
@@ -708,7 +708,7 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// These qualifiers have no effect.
+    /// These qualifiers have no effect, as `const _` items are unnameable.
     pub UNUSED_VISIBILITIES,
     Warn,
     "detect visibility qualifiers on `const _` items"
