nv50/ir: remove hacky global per-sample interpolation setting

Now that inputs are correctly annotated with interpolation location,
don't try to divine whether all inputs should be per-sample-interpolated
or not.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
nvc0/ir: do quadops on the right texture coordinates for TXD

handleTEX moves the layer as the first argument. This makes sure that
the quadops deal with the texture coordinates.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: <mesa-stable@lists.freedesktop.org>
nvc0/ir: use manual TXD when offsets are involved

Something about how we're implementing offsets for TXD is wrong, just
flip to the generic quadop-based implementation in that case.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
nvc0/ir: fill offset in properly for TXD

Apparently TXD wants its offset differently than TEX, accepting it in
the upper bits of the layer index. Unclear what happens when this is
combined with indirect sampler indexing.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>