libxl: implement virConnectBaselineCPU
libxl: implement virConnectBaselineCPU

Akin to previous commit but for "virsh cpu-baseline" which
computes a baseline CPU for a set of host cpu elements.

Signed-off-by: Joao Martins <7c86cc079af931b7847bbaae227ac1245d2901a0@oracle.com>
Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

zippy2/libvirt,olafhering/libvirt,crobinso/libvirt,libvirt/libvirt,crobinso/libvirt,datto/libvirt,nertpinx/libvirt,eskultety/libvirt,libvirt/libvirt,VenkatDatta/libvirt,zippy2/libvirt,andreabolognani/libvirt,jardasgit/libvirt,eskultety/libvirt,taget/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,eskultety/libvirt,jfehlig/libvirt,libvirt/libvirt,olafhering/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,nertpinx/libvirt,jardasgit/libvirt,eskultety/libvirt,andreabolognani/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,datto/libvirt,taget/libvirt,crobinso/libvirt,jardasgit/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,jfehlig/libvirt,taget/libvirt,andreabolognani/libvirt,nertpinx/libvirt,datto/libvirt,zippy2/libvirt,nertpinx/libvirt,taget/libvirt,olafhering/libvirt,taget/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,datto/libvirt,eskultety/libvirt,jfehlig/libvirt,olafhering/libvirt,datto/libvirt,andreabolognani/libvirt,zippy2/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,libvirt/libvirt,crobinso/libvirt,andreabolognani/libvirt