I would agree in full, those oddball machines don't come up very often. But when they do, its really nice to have something that makes as few assumptions about the underlying hardware as possible. If I recall correctly C89 doesn't make any requirements about size (except that sizeof(char) is always 1).
It is rare that libraries get rewritten from the ground up, so this would be the perfect time to get the code right.
It is rare that libraries get rewritten from the ground up, so this would be the perfect time to get the code right.