references.
(nlm_swap_auxiliary_headers_{in,out}): The copyright length is
only one byte.
(nlm_get_symtab_upper_bound): Include debugging symbols in symbol
count.
(nlm_slurp_symbol_table): Make symlength unsigned. Read debugging
symbols as BFD local symbols.
(nlm_write_object_contents): Don't bother writing out exported
symbols more than once; they now appear in the symbol table more
than once (with and without a prefix) if necessary. Set offset
values to be non-zero as NLMLINK does.
