[turbofan] Don't constant-fold ACCESSOR properties.

test/mjsunit/regress/regress-crbug-686102.js

Index: test/mjsunit/regress/regress-crbug-686102.js
diff --git a/test/mjsunit/regress/regress-crbug-686102.js b/test/mjsunit/regress/regress-crbug-686102.js
new file mode 100644
index 0000000000000000000000000000000000000000..13f45035418f87cce3de5314f43bdedb8d828fbe
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-686102.js
@@ -0,0 +1,15 @@
+// Copyright 2017 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 a = [];
+Object.freeze(a);
+function foo() {
+  return a.length;
+}
+assertEquals(0, foo());
+assertEquals(0, foo());
+%OptimizeFunctionOnNextCall(foo);
+assertEquals(0, foo());