u_intNN_t for netinet/in.h?

[Roland McGrath]

When libc is configured for the hurd with libio, including <endian.h> and
<stdio.h> and <netinet/in.h> does not result in including <sys/types.h>
(only <bits/types.h>) and so u_int32_t (vs uint32_t) is not defined and so
the htontest.c test program did not compile until I made it get <sys/types.h>.

Is this a good thing or a bad thing?  On Linux, somehow or other it winds
up including <sys/types.h> and defining those types and so there is no problem.
Should u_int32_t be guaranteed to be defined by one of those other headers?