Fix re-indexing for literals in do-expressions

test/mjsunit/harmony/regress/regress-crbug-578038.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.
+
+// Flags: --harmony-do-expressions
+
+(function testWithoutOtherLiteral() {
+  var result = ((x = [...[42]]) => x)();
+  assertEquals(result, [42]);
+})();
+
+(function testWithSomeOtherLiteral() {
+  []; // important: an array literal before the arrow function
+  var result = ((x = [...[42]]) => x)();  // will core dump, if not fixed.
+  assertEquals(result, [42]);
+})();