o Build syscons(9)'s splash support if both sc and splash are enabled.
o Include opt_splash.h for vt(9) to know when splash device is enabled.
o Build logo_freebsd.c only if splash and vt are enabled.
o Include opt_compat.h to know when we have to respect compatibility.

Sponsored by:	The FreeBSD Foundation
Use correct casts in gcc's emmintrin.h for the first arguments of the
following builtin functions:

* __builtin_ia32_pslldi128() takes __v4si instead of __v8hi
* __builtin_ia32_psllqi128() takes __v2di instead of __v8hi
* __builtin_ia32_psradi128() takes __v4si instead of __v8hi

This should fix the following errors when building the LINT kernel with
gcc:

sys/crypto/aesni/aesni_wrap.c:191: error: incompatible type for argument 1 of
'__builtin_ia32_psradi128'
sys/crypto/aesni/aesni_wrap.c:195: error: incompatible type for argument 1 of
'__builtin_ia32_pslldi128'

MFC after:	3 days