Add explicit_bzero entity.


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45726 c2e8774f-c49f-e111-b436-862b2bbc8956
Document __FreeBSD_version 1100037.


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45727 c2e8774f-c49f-e111-b436-862b2bbc8956