v8/test/mjsunit/regress/regress-662845.js

// Copyright 2016 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.

// Flags: --allow-natives-syntax

function foo(x) {
  (function() {
    x = 1;
  })();
  return arguments[0];
};
%PrepareFunctionForOptimization(foo);
assertEquals(1, foo(42));
assertEquals(1, foo(42));
%OptimizeFunctionOnNextCall(foo);
assertEquals(1, foo(42));