Banish caddr_t (mostly), use Datum where appropriate.

src/backend/commands/async.c

src/backend/libpq/pqcomm.c

src/backend/postmaster/postmaster.c

src/backend/storage/file/fd.c

src/backend/storage/ipc/ipc.c

src/backend/storage/ipc/sinvaladt.c

src/backend/storage/lmgr/proc.c

src/backend/storage/smgr/smgr.c

src/backend/tcop/postgres.c

src/backend/utils/init/postinit.c

src/include/storage/ipc.h