KVM: x86: Refactor persistent CPU state This patch aligns the KVM-related layout and encoding of the CPU state to be saved to disk or migrated with qemu-kvm. The major differences are reordering of fields and a compressed interrupt_bitmap into a single number as there can be no more than one pending IRQ at a time. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>