Whoever, having been convicted:-
(a) by a Court in Pakistan of an offence punishable under Chapter XII or Chapter XVII of this Code with imprisonment of either description for a term of three years or upwards,
shall be guilty of any offence punishable under either of those Chapters with the imprisonment for the like term, shall be subject for every such subsequent offence to imprisonment for life, or to imprisonment of either description for a term which may extend to ten years.