Reimplement src/mongo/platform/waitable_atomic.cpp using absolute time. This uses more simple conversions. The implementation is now similar to the Linux version instead of the MacOS version. It should not have any functional change. Reported by: https://infosec.exchange/@david_chisnall/113797905538197081 Reported by: https://github.com/mongodb/mongo/pull/1607#issuecomment-2605593775