Swift static linking bug demo project

When these three conditions are true:

1. build a simple Vapor app using -Xswiftc -static-executable, and
2. that app includes http calls using async-http-client, and
3. there is at least 60 seconds between a previous call and a subsequent call

Then Vapor will segfault.

It only happens when the app was compiled statically.

Demo script

Run the make_bug_go_boom.sh script to demonstrate the crash.