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/object-initializer.js

@@ -0,0 +1,77 @@
+// 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.
+
+switch (1) {
+default:
+  var o = {
+    value: 10,
+    func() {
+      return 234 + this.value;
+    },
+    ["a" + "b"]() {
+      return 456 - this.value;
+    }
+  }
+}
+
+assert(o.func() === 244);
+assert(o.ab() === 446);
+
+switch (1) {
+default:
+  var ab = 5;
+  var cd = 6;
+  o = {
+    ab,
+    cd: 8,
+    cd
+  }
+}
+
+assert(o.ab === 5);
+assert(o.cd === 6);
+
+function exception_expected(str) {
+  try {
+    eval(str);
+    assert(false);
+  } catch (e) {
+    assert(e instanceof SyntaxError);
+  }
+}
+
+// These forms are invalid.
+exception_expected('({ true })');
+exception_expected('({ 13 })');
+exception_expected('({ "x" })');
+
+switch (1) {
+default:
+  // These forms are valid.
+  ({ true: true });
+  ({ 13: 13 });
+  ({ "x": "x" });
+
+  var get = 8;
+  var set = 12;
+  var o = ({ get, set });
+
+  assert(o.get == 8);
+  assert(o.set == 12);
+}
+
+var obj = { get() { return 5; }, set() { return 6; } };
+
+assert (obj.get() === 5);
+assert (obj.set() === 6);