(copy_loop_body): When set const_age_map entry for split dest reg,
verify that it is within the bounds of the map.
(find_splittable_regs): Count number of biv sets, not number of
bivs.  Don't pass result to find_splittable_givs.
(find_splittable_givs): Delete parameter result.  Add local variable result.

From-SVN: r5741