target/i386: log MCE guest and host addresses

target/i386: log MCE guest and host addresses

Patch logs MCE AO, AR messages injected to guest or taken by QEMU itself.
We print the QEMU address for guest MCEs, helps on hypervisors that have
another source of MCE logging like mce log, and when they go missing.

For example we found these QEMU logs:

September 26th 2019, 17:36:02.309        Droplet-153258224: Guest MCE Memory Error at qemu addr 0x7f8ce14f5000 and guest 3d6f5000 addr of type BUS_MCEERR_AR injected   qemu-system-x86_64      amsN    ams3nodeNNNN

September 27th 2019, 06:25:03.234        Droplet-153258224: Guest MCE Memory Error at qemu addr 0x7f8ce14f5000 and guest 3d6f5000 addr of type BUS_MCEERR_AR injected   qemu-system-x86_64      amsN    ams3nodeNNNN

The first log had a corresponding mce log entry, the second didnt (logging
thresholds) we can infer from second entry same PA and mce type.

Signed-off-by: Mario Smarduch <msmarduch@digitalocean.com>
Message-Id: <20191009164459.8209-3-msmarduch@digitalocean.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>