start address for a.out executables. This is useful in the case that
kernel text starts in the second physical page, in which case the
clever hack to work around the problem is defeated.
This option was patterned after the -T flag documented in the ld(1)
man page. (It does not support the undocumented '-Ttext <addr>'
usage, however, since that would require a parser or getopt(3) hacks.)
lukem