vmm: Rework snapshotting of CPU-specific per-vCPU data.

[jhb]

Summary

Previously some per-vCPU state was saved in vmmops_snapshot and other
state was saved in vmmops_vcmx_snapshot. Consolidate all per-vCPU
state into the latter routine and rename the hook to the more generic
'vcpu_snapshot'. Note that the CPU-independent per-vCPU data is still
stored in a separate blob as well as the per-vCPU local APIC data.

[markj]

sys/amd64/vmm/amd/svm.c

2599

"i" is gone.

2644

Elsewhere this is done with svm_set_dirty(svm_sc, vcpu, 0xffffffff);. This code is missing VMCB_CACHE_LBR.

[jhb]

sys/amd64/vmm/amd/svm.c

2644

I might fix that in a separate commit I'll add to the series. This is just a copy/paste of the old code.