Serialize also canonical names of 'interfaceTargetReference'.

pkg/kernel/lib/binary/limited_ast_to_binary.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:kernel/ast.dart';
 import 'package:kernel/binary/ast_to_binary.dart';
 
 /// Writes libraries that satisfy the [predicate].
 ///
 /// Only the referenced subset of canonical names is indexed and written,
@@ skipping 47 matching lines @@
   final List<CanonicalName> referencedNames = <CanonicalName>[];
 
   defaultMemberReference(Member node) {
     _handleReferencedName(node.canonicalName);
   }
 
   visitClassReference(Class node) {
     _handleReferencedName(node.canonicalName);
   }
 
+  visitInterfaceTargetReference(Reference reference) {
+    _handleReferencedName(reference?.canonicalName);
+  }
+
   void _handleReferencedName(CanonicalName name) {
     if (name == null || name.parent == null) return;
     _handleReferencedName(name.parent);
     referencedNames.add(name);
     name.index = -1;
     put(name.name);
   }
 }