All platforms on NetBSD use a shared system call table, so use a
single XML file to describe the system calls available on each NetBSD
platform.
gdb/ChangeLog:
* syscalls/update-netbsd.sh: New file.
* syscalls/netbsd.xml: Regenerate.
* data-directory/Makefile.in: Register `netbsd.xml' in
`SYSCALLS_FILES'