[arm] RPython translation fix for ArmRegisterFile
[arm] RPython translation fix for ArmRegisterFile

moreati/pydgin,futurecore/pydgin,moreati/pydgin,moreati/pydgin,cornell-brg/pydgin,cornell-brg/pydgin,cornell-brg/pydgin,moreati/pydgin,cornell-brg/pydgin,futurecore/pydgin,futurecore/pydgin,futurecore/pydgin