i965: Set dest type to UW for several send messages

i965: Set dest type to UW for several send messages

Without this, on SIMD 16 the send instruction destination will appear
to write more than one destination register, causing the simulator to
report an error.

Of course, the send instruction can actually write more than one
destination register regardless of the type set for the destination,
so this is a bit strange.

Suggested-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>