Serialize also canonical names of 'interfaceTargetReference'.

pkg/kernel/lib/visitor.dart

Index: pkg/kernel/lib/visitor.dart
diff --git a/pkg/kernel/lib/visitor.dart b/pkg/kernel/lib/visitor.dart
index 2aa31fbe2f97882cea08ce149154656b665c1d20..3c65f978f74614678016d50ff4cb397b199d2bad 100644
--- a/pkg/kernel/lib/visitor.dart
+++ b/pkg/kernel/lib/visitor.dart
@@ -253,6 +253,8 @@ class MemberReferenceVisitor<R> {
   R visitFieldReference(Field node) => defaultMemberReference(node);
   R visitConstructorReference(Constructor node) => defaultMemberReference(node);
   R visitProcedureReference(Procedure node) => defaultMemberReference(node);
+
+  R visitInterfaceTargetReference(Reference reference) => null;
 }
 
 class Visitor<R> extends TreeVisitor<R>
@@ -282,6 +284,7 @@ class Visitor<R> extends TreeVisitor<R>
   R visitFieldReference(Field node) => defaultMemberReference(node);
   R visitConstructorReference(Constructor node) => defaultMemberReference(node);
   R visitProcedureReference(Procedure node) => defaultMemberReference(node);
+  R visitInterfaceTargetReference(Reference reference) => null;
 
   R visitName(Name node) => defaultNode(node);
   R visitSupertype(Supertype node) => defaultNode(node);