Sicne the MFC of file 5.21 in r276416, stable/9 cannot be built from any
FreeBSD 8.x version. This is because the build-tools stage requires
libmagic, but lib/libmagic/config.h was generated on -current, and it
now enables using the xlocale.h APIs, which are not supported on 8.x
(and on 9.x before __FreeBSD_version 900506).
See also the start of this thread on -stable:
Applying this diff directly to stable/9 makes it build on 8.4-RELEASE.
Let's first get it into -current, then MFC it after a suitable timeout.