[PATCH] Add clang headers that fix machine-dependent definitions on FreeBSD 9.2

[Ed Maste]

http://bugs.freebsd.org/186247 has been fixed in stable/9 and will be in 9.3

One issue reported in http://bugs.freebsd.org/186958 is still open but the others are now not reproducible.

http://reviews.llvm.org/D3908