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

jerry-core/ecma/operations/ecma-string-object.c

@@ -70,7 +70,7 @@ ecma_op_create_string_object (const ecma_value_t *arguments_list_p, /**< list of
   proto_id = ECMA_BUILTIN_ID_OBJECT_PROTOTYPE;
 #endif /* JERRY_BUILTIN_STRING */
   ecma_object_t *prototype_obj_p = ecma_builtin_get (proto_id);
-#if JERRY_ESNEXT
+
   ecma_object_t *new_target = JERRY_CONTEXT (current_new_target_p);
   if (new_target)
   {
@@ -80,7 +80,7 @@ ecma_op_create_string_object (const ecma_value_t *arguments_list_p, /**< list of
       return ECMA_VALUE_ERROR;
     }
   }
-#endif /* JERRY_ESNEXT */
+
   ecma_object_t *object_p =
     ecma_create_object (prototype_obj_p, sizeof (ecma_extended_object_t), ECMA_OBJECT_TYPE_CLASS);
 
@@ -88,12 +88,11 @@ ecma_op_create_string_object (const ecma_value_t *arguments_list_p, /**< list of
   ext_object_p->u.cls.type = ECMA_OBJECT_CLASS_STRING;
   ext_object_p->u.cls.u3.value = prim_value;
 
-#if JERRY_ESNEXT
   if (new_target)
   {
     ecma_deref_object (prototype_obj_p);
   }
-#endif /* JERRY_ESNEXT */
+
   return ecma_make_object_value (object_p);
 } /* ecma_op_create_string_object */