Re-target for ES.Next (#3901)

A list of changes:
- 'es2015-subset' profile is deprecated, and an 'es.next' profile is added.
- The default profile is changed to 'es.next'
- Renamed the JERRY_ES2015 guard to JERRY_ESNEXT
- Renamed JERRY_ES2015_BUILTIN_* guards to JERRY_BUILTIN_*
- Moved es2015 specific tests to a new 'es.next' subdirectory
- Updated docs, targets, and test runners to reflect these changes

Resolves #3737.

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai dbatyai@inf.u-szeged.hu

tests/jerry/es.next/arguments-iterator.js

@@ -0,0 +1,50 @@
+// 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 arrayPrototypeValues = Array.prototype.values;
+
+function f_mapped() {
+  assert(typeof arguments[Symbol.iterator] === 'function');
+  assert(arguments[Symbol.iterator] === arrayPrototypeValues);
+  assert(Object.hasOwnProperty.call(arguments, Symbol.iterator));
+
+  let sum = 0;
+  for (a of arguments) {
+    sum += a;
+  }
+  return sum;
+};
+
+function f_unmapped(b = 2) {
+  assert(typeof arguments[Symbol.iterator] === 'function');
+  assert(arguments[Symbol.iterator] === arrayPrototypeValues);
+  assert(Object.hasOwnProperty.call(arguments, Symbol.iterator));
+
+  let sum = 0;
+  for (a of arguments) {
+    sum += a;
+  }
+  return sum;
+};
+
+assert(f_mapped(1, 2, 3, 4, 5) === 15);
+assert(f_unmapped(1, 2, 3, 4, 5) === 15);
+
+Object.defineProperty(Array.prototype, "values", { get : function () {
+  /* should not be executed */
+  assert(false);
+}});
+
+assert(f_mapped(1, 2, 3, 4, 5) === 15);
+assert(f_unmapped(1, 2, 3, 4, 5) === 15);