src/third_party/v8/test/mjsunit/regress/regress-crbug-851393.js

// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

var proxy = new Proxy({}, {});

Object.assign(proxy, { b: "boom", 060: "ah", o: "ouch" });