bhyve upstream sync 2019 Sept
Upstreaming OS-8117 from SmartOS:
This merge contains mostly userspace changes to bhyve and currently ignores commit c8edafdabc (OS-8118). Additionally there was some vmm changes that touched both intel and AMD. I ran a test platform on intel hardware as well as AMD (under nested virt via KVM). I tried to exercise both network and disk paths. I ran linux and windows guests and community members tested a few of the BSDs. The patch was also pulled in by the omnios folk and smoke tested there.