Add new runtime tests

tests/jerry/N.arithmetics-bignums.js

@@ -0,0 +1,24 @@
+// 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 big = 2147483646;
+
+big++;
+assert(big == 2147483647);
+
+big += 1;
+assert(big == 2147483648); // overflow on 32bit numbers
+
+big++;
+assert(big == 2147483649); // overflow on 32bit numbers