* dwarf2out.c (gen_subprogram_die): Handle redefinition of an
        extern inline function.

        * dwarf2out.c (reg_loc_descriptor): Fix prototype.
        (concat_loc_descriptor): New function.
        (loc_descriptor): Call it.
        (add_AT_location_description): Also elide the descriptor if both
        halves of a CONCAT are pseudos.
        (add_location_or_const_value_attribute): Recognize CONCAT too.
Bring over from devo/fsf.

From-SVN: r15470