Cycles: Use Displacement type in OSL ShadingSystem.
Cycles: Use Displacement type in OSL ShadingSystem.

Reviewed by: brecht
Differential Revision: https://developer.blender.org/D386

pyrochlore/cycles,tangent-opensource/coreBlackbird,pyrochlore/cycles,pyrochlore/cycles,tangent-opensource/coreBlackbird,tangent-opensource/coreBlackbird