Fix bug with spread rewriting

test/mjsunit/harmony/regress/regress-4696.js

+// Copyright 2016 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 testSpreadIndex() {
+  var result = [...[17, 42]][1];
+  assertEquals(result, 42);
+})();
+
+(function testSpreadProperty() {
+  var result = [...[17, 42]].length;
+  assertEquals(result, 2);
+})();
+
+(function testSpreadMethodCall() {
+  var result = [...[17, 42]].join("+");
+  assertEquals(result, "17+42");
+})();
+
+(function testSpreadSavedMethodCall() {
+  var x = [...[17, 42]];
+  var method = x.join;
+  var result = method.call(x, "+");
+  assertEquals(result, "17+42");
+})();
+
+(function testSpreadAsTemplateTag() {
+  assertThrows(function() { [...[17, 42]] `foo`; }, TypeError)
+})();