handle the special snowflakes that are Integer Indexed Exotic objects

test/mjsunit/es6/indexed-integer-exotics.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
+
+Object.prototype["10"] = "unreachable";
+Object.prototype["7"] = "unreachable";
+Object.prototype["-1"] = "unreachable";
+Object.prototype["-0"] = "unreachable";
+Object.prototype["4294967296"] = "unreachable";
+
+var array = new Int32Array(10);
+
+function check() {
+  for (var i = 0; i < 4; i++) {
+    assertEquals(undefined, array["-1"]);
+    assertEquals(undefined, array["-0"]);
+    assertEquals(undefined, array["10"]);
+    assertEquals(undefined, array["4294967296"]);
+  }
+  assertEquals("unreachable", array.__proto__["-1"]);
+  assertEquals("unreachable", array.__proto__["-0"]);
+  assertEquals("unreachable", array.__proto__["10"]);
+  assertEquals("unreachable", array.__proto__["4294967296"]);
+}
+
+check();
+
+array["-1"] = "unreachable";
+array["-0"] = "unreachable";
+array["10"] = "unreachable";
+array["4294967296"] = "unreachable";
+
+check();
+
+delete array["-0"];
+delete array["-1"];
+delete array["10"];
+delete array["4294967296"];
+
+assertEquals(undefined, Object.getOwnPropertyDescriptor(array, "-1"));
+assertEquals(undefined, Object.getOwnPropertyDescriptor(array, "-0"));
+assertEquals(undefined, Object.getOwnPropertyDescriptor(array, "10"));
+assertEquals(undefined, Object.getOwnPropertyDescriptor(array, "4294967296"));
+assertEquals(10, Object.keys(array).length);
+
+check();
+
+function f() { return array["-1"]; }
+
+for (var i = 0; i < 3; i++) {
+  assertEquals(undefined, f());
+}
+%OptimizeFunctionOnNextCall(f);
+assertEquals(undefined, f());