text: // 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.
  
  function Foo() {}
  var x = new Foo();
  Foo.prototype = 1;
  function foo() { return x instanceof Foo; }
  assertThrows(foo, TypeError);
  