integration test against hvf

[eyberg]

along the lines of https://github.com/nanovms/ops/issues/277

still of 2 minds which one is better here for osx but i'll grab a mac mini for the office so we can reliably build against at least one of these

https://github.com/nanovms/ops/issues/268

[mkhon]

hvf works out of the box and does not require any third-party components. hax is currently broken for me:

qemu-system-x86_64 -m 2G -display none -serial stdio -drive if=none,id=hd0,format=raw,file=/Users/fjoe/work/nanovms/nanos/output/image/disk.raw -device virtio-scsi-pci,id=scsi0 -device scsi-hd,bus=scsi0.0,drive=hd0 -device isa-debug-exit -no-reboot  -device virtio-net,netdev=n0 -netdev user,id=n0,hostfwd=tcp::8080-:8080,hostfwd=tcp::9090-:9090,hostfwd=udp::5309-:5309 -accel hax || exit $(($?>>1))
HAX is working and emulator runs in fast virt mode.
VCPU shutdown request
VCPU shutdown reques

HAX 7.4.1, Core i5 (Macbook Pro 2017), macOS Mojave