scripts/arch-run: Support testing of hvf accel

The tests can be run if Hypervisor.framework API is available:

  https://developer.apple.com/documentation/hypervisor?language=objc#1676667



Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <20200320145541.38578-2-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>