Add support for Symbols when using the 'in' operation (#3202)

The change adds support for the 'in' operation to handle Symbols.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

tests/jerry/es2015/symbol-in.js

@@ -0,0 +1,59 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * 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 test_symbol = Symbol ('Test');
+
+var obj = {};
+
+assert ((test_symbol in obj) === false);
+
+obj[test_symbol] = 'value';
+
+assert ((test_symbol in obj) === true);
+assert (obj[test_symbol] === 'value');
+
+
+var array = [];
+
+assert ((test_symbol in array) === false);
+
+array[test_symbol] = 'value';
+
+assert ((test_symbol in array) === true);
+assert (array[test_symbol] === 'value');
+
+
+assert ((test_symbol in Symbol) === false);
+
+try {
+  test_symbol in test_symbol;
+  assert (false);
+} catch (ex) {
+  assert (ex instanceof TypeError);
+}
+
+try {
+  test_symbol in 3;
+  assert (false);
+} catch (ex) {
+  assert (ex instanceof TypeError);
+}
+
+try {
+  test_symbol in 'Test';
+  assert (false);
+} catch (ex) {
+  assert (ex instanceof TypeError);
+}