Blender Git Loki

Cycles/OpenCL: Remove NULL PTR Workaround

In the current OpenCL implementation we have a work-around for platforms
that didn't support NULL pointers. We used to replace all NULLs and
empty arrays with a pointer to a single byte on the OpenCL Device.

During investigation of {T65924} it was asked to remove this work-around
for testing. This change improves the render times.

SCENE | BEFORE | AFTER
--------------------+--------+-------
bmw27 | 108 | 89
barbershop_interior | 867 | 673
classroom | 270 | 173
fishy_cat | 244 | 196
koro | 249 | 207
pavillon_barcelona | 582 | 414

Note that this change does not fix T65924 it just improves the
rendering performance for OpenCL. We haven't tested this patch on all
platforms so we should keep an eye out on the tracker.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D6391