Enable regular expressions.

- add regular expressions support to JS parser and interpreter;
- add tests for regular expressions.

JerryScript-DCO-1.0-Signed-off-by: Szilard Ledan szledan.u-szeged@partner.samsung.com
JerryScript-DCO-1.0-Signed-off-by: László Langó llango.u-szeged@partner.samsung.com

tests/jerry/regexp-backreference.js

@@ -0,0 +1,27 @@
+// Copyright 2015 Samsung Electronics Co., Ltd.
+// Copyright 2015 University of Szeged.
+//
+// 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 r;
+
+r = new RegExp ("(a)b\\1").exec("aba");
+assert (r[0] == "aba");
+assert (r[1] == "a");
+
+r = new RegExp ("(a)b\\1").exec("b");
+assert (r == undefined);
+
+r = new RegExp ("(a)*b\\1").exec("b");
+assert (r[0] == "b");
+assert (r[1] == undefined);