Delegation implementation: step 1

compiler/rustc_resolve/src/effective_visibilities.rs

@@ -277,7 +277,8 @@ impl<'r, 'ast, 'tcx> Visitor<'ast> for EffectiveVisibilitiesVisitor<'ast, 'r, 't
             | ast::ItemKind::TraitAlias(..)
             | ast::ItemKind::MacroDef(..)
             | ast::ItemKind::ForeignMod(..)
-            | ast::ItemKind::Fn(..) => return,
+            | ast::ItemKind::Fn(..)
+            | ast::ItemKind::Delegation(..) => return,
         }
     }
 }