kernel compile broken in latest HEAD

I just saw this breakage while compiling a kernel on HEAD updated
minutes ago:

--------------------------------------------------------------
>>> stage 3.2: building everything
--------------------------------------------------------------
cc1: warnings being treated as errors
In file included from /usr/src/sys/modules/linux/../../compat/linux/linux_ioctl.c:91:
_at_/contrib/v4l/videodev2.h:430: warning: declaration does not declare anything
_at_/contrib/v4l/videodev2.h:460: warning: declaration does not declare anything
_at_/contrib/v4l/videodev2.h:837: warning: declaration does not declare anything
_at_/contrib/v4l/videodev2.h:930: warning: declaration does not declare anything
_at_/contrib/v4l/videodev2.h:1478: warning: declaration does not declare anything
_at_/contrib/v4l/videodev2.h:1600: warning: declaration does not declare anything
_at_/contrib/v4l/videodev2.h:1651: warning: declaration does not declare anything
--- linux_ioctl.o ---
*** [linux_ioctl.o] Error code 1

make: stopped in /usr/src/sys/modules/linux
1 error

These line numbers all point at nameless unions.

Seems to me that a union needs a name, otherwise one cannot
access its contents.

I simply named them all x to get the kernel to compile, which
succeeded.

It seems that none of these unions are used at the moment.

-- 
Gary Jennejohn