Notice that uptime is used only as last resort, when no other cheaper unix compatible strategy is available. Therefore, call to sysctl can stay, as will just silently fail on Windows.
Something you migh be interested into: https://sourceforge.net/projects/gnuwin32/
So yeah, we'd need to upgrade. Or maybe we'd back-patch these changes. But it's good to know they are included "upstream" now.
I also found the other issue with the missing throttle functionality. The reason is that libthread is missing. I'll check with Maurizio.
Thanks! Frank