Fix keyed access of primitive objects in the runtime.

test/mjsunit/primitive-keyed-access.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.
+
+Object.defineProperty(Number.prototype, "0",
+    { set: function(v) { set = v; }});
+Object.defineProperty(String.prototype, "0",
+    { set: function(v) { set = v; }});
+Object.defineProperty(String.prototype, "3",
+    { set: function(v) { set = v; }});
+
+var set;
+var n = 1;
+set = 0;
+n[0] = 100;
+assertEquals(100, set);
+var s = "bla";
+s[0] = 200;
+assertEquals(100, set);
+s[3] = 300;
+assertEquals(300, set);
+
+assertThrows(function(){"use strict"; var o = "123"; o[1] = 10; });
+assertThrows(function(){"use strict"; var o = ""; o[1] = 10; });
+assertThrows(function(){"use strict"; var o = 1; o[1] = 10; });
+
+assertThrows(function() {
+  "use strict";
+  var sym = Symbol('66');
+  sym.a = 0;
+});
+
+assertThrows(function() {
+  "use strict";
+  var sym = Symbol('66');
+  sym['a' + 'b'] = 0;
+});
+
+assertThrows(function() {
+  "use strict";
+  var sym = Symbol('66');
+  sym[62] = 0;
+});