branches: 1.5.6; 1.5.16;
Change CMSG_SPACE and CMSG_LEN to provide Integer Constant Expressions
again. This was changed in sys/socket.h r1.51 to work around fallout
from the IPv6 aux data migration. It broke the historic ABI on some
platforms. This commit restores compatibility for netbsd32 code on such
platforms and provides a template for future changes to the CMSG_*
alignment. Revert PCC/Clang workarounds in postfix and tmux.