All the elements of these structs are char anyway, so it won't hurt
performance.
Bump warns back up to the default.
# we likely should have CTASSERTS to make sure they are the right size.
# but with libarchive based tar maybe we shouldn't bother.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.