get a cross compiler sooner

clang is already in the archives and already supports cross-compiling

just

clang -target arm-linux-gnueabihf foo.c -o foo

all it needs to do this is a cross binutils, which, unlike gcc cross,
it doesn't have any cross build dependencies. Can we get get
a cross binutils uploaded pronto?

the insturctions from here work great
https://wiki.debian.org/BuildingCrossCompilers

-Shawn

PS. The include paths when cross compiling with clang are wrong in the
debian versions, but fixed upstream, see bug 729933