MapRegisterIndex
int32 dwarfReg = toDwarf->MapRegisterIndex(i);
virtual int32 MapRegisterIndex(int32 index) const = 0;
context.RegisterRule(fToDwarfRegisterMap->MapRegisterIndex(
context.RegisterRule(fToDwarfRegisterMap->MapRegisterIndex(
int32 index = fFromDwarfMap->MapRegisterIndex(dwarfIndex);
int32 reg = typeContext->FromDwarfRegisterMap()->MapRegisterIndex(