Remove polymorphization

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -269,7 +269,6 @@ provide! { tcx, def_id, other, cdata,
     lookup_default_body_stability => { table }
     lookup_deprecation_entry => { table }
     params_in_repr => { table }
-    unused_generic_params => { table_direct }
     def_kind => { cdata.def_kind(def_id.index) }
     impl_parent => { table }
     defaultness => { table_direct }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1767,10 +1767,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             {
                 record!(self.tables.mir_coroutine_witnesses[def_id.to_def_id()] <- witnesses);
             }
-
-            let instance = ty::InstanceKind::Item(def_id.to_def_id());
-            let unused = tcx.unused_generic_params(instance);
-            self.tables.unused_generic_params.set(def_id.local_def_index, unused);
         }
 
         // Encode all the deduced parameter attributes for everything that has MIR, even for items

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -395,7 +395,6 @@ define_tables! {
     inherent_impls: Table<DefIndex, LazyArray<DefIndex>>,
     associated_types_for_impl_traits_in_associated_fn: Table<DefIndex, LazyArray<DefId>>,
     opt_rpitit_info: Table<DefIndex, Option<LazyValue<ty::ImplTraitInTraitData>>>,
-    unused_generic_params: Table<DefIndex, UnusedGenericParams>,
     // Reexported names are not associated with individual `DefId`s,
     // e.g. a glob import can introduce a lot of names, all with the same `DefId`.
     // That's why the encoded list needs to contain `ModChild` structures describing all the names