Swift build on FreeBSD

[lin72h]

I've been watching airyx for a while, great project, thanks for reviving the NextBSD!

Just found out the Swift on FreeBSD PR has been fixed

swiftlang/swift#38335

hopeful you get swift into your future release

[mszoek]

Fixed, but not merged yet. Hopefully soon! I suppose we could build with the patch though.

[lin72h]

I think we can take a incremental step:

• make in base libdispatch work PR
  This make use the eventfd which introduced in FreeBSD 13, so it align more to the Linux libdispatch implementation, thus less core need to be changed. Next step could be use the macOS implementation

• make the CFRunLoop works PR
  This implementation doesn't use Machport, but kqueue, so could be first step to make it work.
  The next step could be implemented using our native MachPort

• Try to build the Swif 5.7 Version using @erde74 's patch [PR] Fix build on FreeBSD swiftlang/swift#38335 (comment)

[mszoek]

Sounds great! Do you want to take a shot at updating libdispatch?