Changes for AIX compilation to get CPU of running thread. hz is inter… (#12744)
* Changes for AIX compilation to get CPU of running thread. hz is internal variable in AIX, hence changing to hz1 in window_functions.cc so that all OS shall work
Co-authored-by: madurais <root@telesto10.in.ibm.com>
Co-authored-by: tvkai <vamshikrishna@in.ibm.com>