r600: Delay emission of texture gradients and lookup offsets

r600: Delay emission of texture gradients and lookup offsets

Gradients used in texture lookups and the offsets must reside in the
same fetch clause (the first is imposed by the hardware and the second
is expected by sb). In order to ensure that no ALU clause is inserted
between emission and use of these, delay the emission of these
instructions until the texture instruction using them is also emitted.

This is needed in preparation for the correction of the texture array
indices.

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>