Elaborate lint explanation

Jules-Bertholet · Jules-Bertholet · commit 35e13f7fa6b6 · 2025-11-08T22:48:36.000-05:00
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
@@ -707,7 +707,7 @@ 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"
