v8/test/mjsunit/compiler/regress-4470-1.js

// Copyright 2015 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() {}
Foo.prototype.x = 0;
function foo(f) {
  f.x = 1;
}
%PrepareFunctionForOptimization(foo);
foo(new Foo);
foo(new Foo);
%OptimizeFunctionOnNextCall(foo);
foo(new Foo);
assertEquals(Foo.prototype.x, 0);