Created originally on Bitbucket by Joannah Nanjekye (joannah nanjekye)
This PR adds several missing posix attributes to fix #2375. It has implementation for:
- getgrouplist
- sched_rr_get_interval
- sched_getscheduler
- sched_setscheduler
- sched_getparam
- sched_setparam
Wait on Review. I need to fix some branch mixes.