Remove ES_NEXT macro (#4915)

- remove all '#JERRY_ESNEXT' macro
- remove 5.1 build profile, update test runner accordingly (Note: all builtins are turn on by default)
- move tests from tests/jerry/esnext into tests/jerry, concatenate files with same names
- add skiplist to some snapshot tests that were supported only in 5.1
- fix doxygen issues that were hidden before (bc. of es.next macro)

Co-authored-by: Martin Negyokru negyokru@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Adam Szilagyi aszilagy@inf.u-szeged.hu

tests/jerry/class-fields3.js

@@ -0,0 +1,83 @@
+// 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.
+
+function check_property(obj, name, value)
+{
+  property = Object.getOwnPropertyDescriptor(obj, name)
+  assert(typeof property === "object")
+  assert(property.value === value)
+}
+
+var o = {}
+var name = "Pro"
+var res = 0
+var counter = 0
+
+function f1() {
+  counter++
+}
+
+class C1 {
+  static
+    v\u0061r
+  static Prop =
+    res
+    =
+    "msg"
+  static
+    Prop
+    =
+    f1()
+  static [name + "p"] = (f1(), o)
+  static 22 = 3 * 4  ;static 23 = 5 + 6
+  static 'a b'
+}
+
+check_property(C1, "var", undefined)
+check_property(C1, "Prop", o)
+check_property(C1, 22, 12)
+check_property(C1, 23, 11)
+check_property(C1, "a b", undefined)
+assert(res === "msg")
+assert(counter === 2)
+
+counter = 0
+class C2 {
+  static a = (assert(++counter === 6), "x")
+  static [(assert(++counter === 1), "b")]
+  static [(assert(++counter === 2), "f")]() {}
+  static [(assert(++counter === 3), "c")] = (assert(++counter === 7), this);
+  [(assert(++counter === 4), "a")]
+  static [(assert(++counter === 5), "d")];static e = (assert(++counter === 8), C2)
+}
+
+assert(counter === 8)
+check_property(C2, "a", "x")
+check_property(C2, "b", undefined)
+check_property(C2, "c", C2)
+check_property(C2, "d", undefined)
+check_property(C2, "e", C2)
+
+res = new C2
+check_property(res, "a", undefined)
+
+let C3 = class C4 {
+  static f() {}
+  static xx = C4
+  static yy = this
+}
+
+assert(Reflect.ownKeys(C3).toString() === "length,name,prototype,f,xx,yy")
+check_property(C3, "xx", C3)
+check_property(C3, "yy", C3)