add support for 8.1 SDK
(temp): split low/high register mask in OperandMask
(temp): begin converting to setLowHighRegisterMasks
(temp): continuing conversion...
(temp): continuing conversion...
(temp): bring arm up to snuff
(temp): rename RegisterMask to BoundedRegisterMask
(temp): remove unused arm utilities / constants
(temp): begin typedeffing RegisterMask
(temp): further typedef RegisterMask
(temp): further typedef RegisterMask
(temp): further typedef RegisterMask......
(temp): finish typedef RegisterMask
(temp): remove old 32-bit registerMask stuff
(temp): begin typdeffing Register
(temp): make RegisterMask a class
(temp): catch arm up
(temp): begin renaming lir:: types
(temp): finish renaming lir:: types (fixup arm)
(temp): rename lir::Register to lir::RegisterPair