Cosmetic. Move pre_xol_rip_insn() and handle_riprel_post_xol() up to
the closely related handle_riprel_insn(). This way it is simpler to
read and understand this code, and this lessens the number of ifdef's.
While at it, update the comment in handle_riprel_post_xol() as Jim
suggested.
TODO: rename them somehow to make the naming consistent.