Support 'delete' and 'void' operators in parser.

tests/jerry/N.delete.js

@@ -0,0 +1,27 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var a = 1;
+assert (a === 1);
+assert (delete a === true);
+assert (a === undefined);
+var a = [1];
+assert (a[0] === 1);
+assert (delete a[0] === true);
+assert (a[0] == undefined);
+assert (delete 0 === true);
+var b = {c:0};
+assert (b.c === 0);
+assert (delete b.c === true);
+assert (b.c === undefined);