Support file verification in MAC.
- Add VCREAT flag to indicate when a new file is being created
- Add VVERIFY to indicate verification is required
- Both VCREAT and VVERIFY are only passed on the MAC method vnode_check_open and are removed from the accmode after
- Add O_VERIFY flag to rtld open of objects
- Add 'v' flag to __sflags to set O_VERIFY flag.
Submitted by: Steve Kiernan <stevek@juniper.net>
Obtained from: Juniper Networks, Inc.
GitHub Pull Request: https://github.com/freebsd/freebsd/pull/27
Relnotes: yes