Nuke register keyword usage, rename pread to preadfd, and open input files FD_CLOEXEC.
Nuke register keyword usage, rename pread to preadfd, and open
input files FD_CLOEXEC.

Obtained from: NetBSD

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase