* aoutx.h: Rewrite symbol duplicate elimination to use BFD hash

	* aoutx.h: Rewrite symbol duplicate elimination to use BFD hash
	tables.
	(struct stringtab_entry, struct stringtab_data): Remove.
	(HASHMAXLEN, HASH_CHAR, hash, compare, log2, emit_strtab): Remove.
	(struct strtab_hash_entry, struct strtab_hash): Define.
	(strtab_hash_newfunc, strtab_hash_lookup): Define.
	(stringtab_free, emit_stringtab): Define.
	(stringtab_init, add_to_stringtab): Rewrite.
	(NAME(aout,write_syms)): Use new stringtab code.
	(struct aout_final_link_info, NAME(aout,final_link)): Likewise.
	(aout_link_write_symbols, aout_link_write_other_symbol): Likewise.