Waiting for Individual tasks in task_group API (#1887)

Author: kboyarinov

include/oneapi/tbb/detail/_config.h

@@ -552,4 +552,8 @@
 #define TBB_EXT_CUSTOM_ASSERTION_HANDLER 202510
 #endif
 
+#if __TBB_PREVIEW_TASK_GROUP_EXTENSIONS
+#define TBB_HAS_TASK_GROUP_WAIT_FOR_SINGLE_TASK 202603
+#endif
+
 #endif // __TBB_detail__config_H