i965: Avoid using float type for raw moves, to work around SNB issue.

i965: Avoid using float type for raw moves, to work around SNB issue.

The SNB alt-mode math does the denorm and inf reduction even for a
"raw MOV" like we do for g0 message header setup, where we are moving
values that aren't actually floats.  Just use UD type, where raw MOVs
really are raw MOVs.

Fixes glxgears since c52adfc2e1d130effea940e75690897eb5d3ceaa, but no
piglit tests had regressed(!)