aout_register_t
aout_register_t a_midmag; /* flags<<26 | mid<<16 | magic */
aout_register_t a_text; /* text segment size */
aout_register_t a_data; /* initialized data size */
aout_register_t a_bss; /* uninitialized data size */
aout_register_t a_syms; /* symbol table size */
aout_register_t a_entry; /* entry point */
aout_register_t a_trsize; /* text relocation size */
aout_register_t a_drsize; /* data relocation size */