fix save-analysis

Author: lcnr

compiler/rustc_save_analysis/src/dump_visitor.rs

@@ -320,6 +320,15 @@ impl<'tcx> DumpVisitor<'tcx> {
         for param in generics.params {
             match param.kind {
                 hir::GenericParamKind::Lifetime { .. } => {}
+                hir::GenericParamKind::Type {
+                    synthetic: Some(hir::SyntheticTyParamKind::ImplTrait),
+                    ..
+                } => {
+                    return self
+                        .nest_typeck_results(self.tcx.hir().local_def_id(param.hir_id), |this| {
+                            this.visit_generics(generics)
+                        });
+                }
                 hir::GenericParamKind::Type { .. } => {
                     let param_ss = param.name.ident().span;
                     let name = escape(self.span.snippet(param_ss));
@@ -351,7 +360,8 @@ impl<'tcx> DumpVisitor<'tcx> {
                 hir::GenericParamKind::Const { .. } => {}
             }
         }
-        self.visit_generics(generics);
+
+        self.visit_generics(generics)
     }
 
     fn process_fn(