v3d: set instance id to 0 at start of tile

PTB assumes that base instance to be 0 at start of tile, but hw would
not do that, we need to set it. It is worth to note that the opcode
name is somewhat confusing as what it really sets is the base
instance. We could rename the opcode, but then the name would be
different to the original Broadcom name, so confusing in any case.

This fixes several dEQP-GLES3 and dEQP-GLES31 tests that passes
individually, but started to fail depending on other tests running
before using base instance different to zero.

This is the backport of a Vulkan patch that fixed some Vulkan CTS
tests that start to fails after some other tests used an instance id.

CC: 20.2 20.1 <mesa-stable@lists.freedesktop.org>

Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6447>

src/gallium/drivers/v3d/v3dx_rcl.c

@@ -440,6 +440,13 @@ v3d_rcl_emit_generic_per_tile_list(struct v3d_job *job, int layer)
                 fmt.primitive_type = LIST_TRIANGLES;
         }
 
+#if V3D_VERSION >= 41
+        /* PTB assumes that value to be 0, but hw will not set it. */
+        cl_emit(cl, SET_INSTANCEID, set) {
+           set.instance_id = 0;
+        }
+#endif
+
         cl_emit(cl, BRANCH_TO_IMPLICIT_TILE_LIST, branch);
 
         v3d_rcl_emit_stores(job, cl, layer);