(output_call_frame_info): Change FDE CIE offset to
be section name rather than 0.
(gen_subprogram_die): Only emit DW_AT_external if origin is NULL.
Only call equate_decl_number_to_die if origin is NULL.
(dwarfout_begin_function): In code that computes offset of frame
pointer, change 4 to UNITS_PER_WORD.

From-SVN: r12545