Recently CPU hardware vendors have started to support a new structure
inside the CPU package topology known as a "die". Thus the hierarchy
is now:

  sockets > dies > cores > threads

This adds support for "dies" in the XML parser, with the value
defaulting to 1 if not specified for backwards compatibility.

For example a system with 64 logical CPUs might report

   <topology sockets="4" dies="2" cores="4" threads="2"/>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

We do not fill out qemuCaps->arch when parsing status XML.

Use def->os.arch like we do for PPC.

This fixes hotplug after daemon restart for domains that use
a user alias for the implicit pci-root on x86.

https://bugzilla.redhat.com/show_bug.cgi?id=1518148

Our test data used a lot of different qemu binary paths and some
of them were based on downstream systems.

Note that there is one file where I had to add "accel=kvm" because
the qemuargv2xml code parses "/usr/bin/kvm" as virt type="kvm".
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

The cpu hotplug operation is rather complex so the testing code needs to
provide quite lot of data and monitor conversations to successfully test
it. The code mainly tests the selection of cpus according to the target
count request.