Support for M1 MacBook Simulators

[Neutron]

Hey Igor,

I believe I encountered this in the past.
https://lists.zx2c4.com/pipermail/wireguard/2021-September/007001.html

I'm not sure what your exact setup is since you mentioned it's a separate project presumably depending on WireGuardKit, but I can build libwg-go for arm64 just fine using the trick I mentioned in the linked thread. Just add this flag to Sources/WireGuardKitGo/Makefile.
GOOS_iphonesimulator := ios

Hope it helps.