Since the upstream for cddl code is now illumos not sun, mechanically
convert all sun #ifdef's to illumos #ifdef's which have been used in all
newer code for some time.
Also do a manual pass to correct the use if #ifdef comments as per style(9)
as well as few uses of #if defined(__FreeBSD__) vs #ifndef illumos.
MFC after: 1 month
Sponsored by: Multiplay
On some architectures (powerpc), char is unsigned by default, which means
comparisons against -1 always fail, so the programs get stuck in an
infinite loop.
MFC after: 1 week
