Fix #127464: Disable HIPRT point clouds to fix performance regression

Temporarily disable point cloud rendering in HIPRT to fix a performance
regression triggered by increased register preasure until
a better solution can be developed.

Pull Request: https://projects.blender.org/blender/blender/pulls/127738

intern/cycles/kernel/device/hiprt/common.h

@@ -318,7 +318,10 @@ ccl_device_inline bool point_custom_intersect(const hiprtRay &ray,
                                               void *payload,
                                               hiprtHit &hit)
 {
-#  ifdef __POINTCLOUD__
+  /* Point cloud intersections are currently disabled to decrease register pressure in the ray
+   * tracing kernels. This increases the number of inflight ray traversal waves, and fixes the
+   * performance regression reported in #127464 */
+#  if defined(__POINTCLOUD__) && 0
   RayPayload *local_payload = (RayPayload *)payload;
   KernelGlobals kg = local_payload->kg;
   int object_id = kernel_data_fetch(user_instance_id, hit.instanceID);