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

jerry-core/ecma/operations/ecma-objects-arguments.c

@@ -140,7 +140,7 @@ ecma_op_create_arguments_object (ecma_object_t *func_obj_p, /**< callee function
 
   ecma_property_descriptor_t prop_desc = ecma_make_empty_property_descriptor ();
 
-#if ENABLED (JERRY_ES2015)
+#if ENABLED (JERRY_ESNEXT)
   /* ECMAScript v6, 9.4.4.6.7, 9.4.4.7.22 */
   ecma_string_t *symbol_p = ecma_op_get_global_symbol (LIT_GLOBAL_SYMBOL_ITERATOR);
 
@@ -154,7 +154,7 @@ ecma_op_create_arguments_object (ecma_object_t *func_obj_p, /**< callee function
 
   JERRY_ASSERT (ecma_is_value_object (prop_value_p->value));
   ecma_deref_object (ecma_get_object_from_value (prop_value_p->value));
-#endif /* ENABLED (JERRY_ES2015) */
+#endif /* ENABLED (JERRY_ESNEXT) */
 
   /* 13. */
   if (!is_strict)