Build failure 'wmmintrin.h' file not found

Hi,

I'm seeing the following build-error trying to build 12-current from 
10-stable:

xxx/freebsd/sys/crypto/aesni/aesni_ghash.c:75:10: fatal error: 
'wmmintrin.h' file not found
#include <wmmintrin.h>

Missing header exists:

xxx/freebsd/contrib/llvm/tools/clang/lib/Headers/wmmintrin.h

Missing include directory or compiler magic?

--HPS