[test] copy revoked proxy tests for array-concat to new files

test/mjsunit/es6/array-concat-revoked-proxy-2.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 testConcatRevokedProxyToArray() {
+  "use strict";
+  var handler = {
+    get(_, name) {
+      if (name === Symbol.isConcatSpreadable) {
+        p.revoke();
+      }
+      return target[name];
+    }
+  }
+
+  var target = [];
+  var p = Proxy.revocable(target, handler);
+  assertThrows(function() { [].concat(p.proxy); }, TypeError);
+})();