nv50,nvc0: disable DEPTH_RANGE_NEAR/FAR clipping during blit

We send position.z == 0, DEPTH_RANGE may be some arbitrary range
not including 0 (for exmaple in piglit's hiz tests).

src/gallium/drivers/nv50/nv50_surface.c

@@ -976,6 +976,8 @@ nv50_blit_3d(struct nv50_context *nv50, const struct pipe_blit_info *info)
 
    BEGIN_NV04(push, NV50_3D(VIEWPORT_TRANSFORM_EN), 1);
    PUSH_DATA (push, 0);
+   BEGIN_NV04(push, NV50_3D(VIEW_VOLUME_CLIP_CTRL), 1);
+   PUSH_DATA (push, 0x1);
 
    /* Draw a large triangle in screen coordinates covering the whole
     * render target, with scissors defining the destination region.

src/gallium/drivers/nvc0/nvc0_3d.xml.h

@@ -1041,7 +1041,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define NVC0_3D_VIEWPORT_TRANSFORM_EN				0x0000192c
 
 #define NVC0_3D_VIEW_VOLUME_CLIP_CTRL				0x0000193c
-#define NVC0_3D_VIEW_VOLUME_CLIP_CTRL_UNK0			0x00000001
+#define NVC0_3D_VIEW_VOLUME_CLIP_CTRL_DEPTH_RANGE_0_1		0x00000001
 #define NVC0_3D_VIEW_VOLUME_CLIP_CTRL_UNK1__MASK		0x00000006
 #define NVC0_3D_VIEW_VOLUME_CLIP_CTRL_UNK1__SHIFT		1
 #define NVC0_3D_VIEW_VOLUME_CLIP_CTRL_UNK1_UNK0			0x00000000

src/gallium/drivers/nvc0/nvc0_surface.c

@@ -869,6 +869,8 @@ nvc0_blit_3d(struct nvc0_context *nvc0, const struct pipe_blit_info *info)
       z += 0.5f * dz;
 
    IMMED_NVC0(push, NVC0_3D(VIEWPORT_TRANSFORM_EN), 0);
+   IMMED_NVC0(push, NVC0_3D(VIEW_VOLUME_CLIP_CTRL), 0x2 |
+              NVC0_3D_VIEW_VOLUME_CLIP_CTRL_DEPTH_RANGE_0_1);
    BEGIN_NVC0(push, NVC0_3D(VIEWPORT_HORIZ(0)), 2);
    PUSH_DATA (push, nvc0->framebuffer.width << 16);
    PUSH_DATA (push, nvc0->framebuffer.height << 16);