[Mesa-dev] gallivm integer support base pieces v2

[Dave Airlie]

This is a second send of the gallivm integer opcode support.

This doesn't add the opcodes yet, just sets the basic gallivm
infrastructure changes that are needed to add the opcodes.

I've gone with Jose's suggestion to make MOV use floats and
cast the const vecs, his llvm-fu is way better than mine :)

I've also moved to a different enum than util_format for types.

Dave.