This is the 3rd version for POSIX(OFF) on z/OS. It replaces previous proposals in D110349 and D117375. This patch will help out other platforms where threading support can be determined and/or switched at run-time like AIX.
The full support on z/OS for POSIX(OFF) depends on the following, additional patches from version 2 (D117375). Eventually they need to be landed as well. I'm listing them just for reference:
Please be aware that this revision doesn't include the necessary work for: