[VIRT-263 # ARMv8.1-VHE Virtual Host Extensions ]

Reorg ARMMMUIdx again; this time, do not overlap EL1&0 and EL2&0 mmu_idx. This makes debugging a bit easier.

Fix one more bug in EL2&0 selection. This was not the last, because a nested kernel does not yet boot.

[VIRT-327 # Richard's upstream QEMU work ]

Another round of aa32 decodetree patches. Another round of arm hflags patches. Review of and some patches for cpu watchpoints.

r~