Implement negative bounds

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -530,6 +530,10 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         associated_ty: Option<(&'static str, Ty<'tcx>)>,
         mut body_id: LocalDefId,
     ) {
+        if trait_pred.skip_binder().polarity == ty::ImplPolarity::Negative {
+            return;
+        }
+
         let trait_pred = self.resolve_numeric_literals_with_default(trait_pred);
 
         let self_ty = trait_pred.skip_binder().self_ty();