Disable merging simulates across captured objects.

test/mjsunit/regress/regress-416730.js

+// Copyright 2014 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
+
+var d = {x: undefined, y: undefined};
+
+function Crash(left, right) {
+  var c = {
+    x: right.x - left.x,
+    y: right.y - left.y
+  };
+  return c.x * c.y;
+}
+
+var a = {x: 0.5, y: 0};
+var b = {x: 1, y: 0};
+
+for (var i = 0; i < 3; i++) Crash(a, b);
+%OptimizeFunctionOnNextCall(Crash);
+Crash(a, b);
+
+Crash({x: 0, y: 0.5}, b);