nvc0: set local mem size for compute on gv100
This is required when the shader uses local memory for arrays or spills. I really dislike how it's done right now, but oh well, it's the same for other gens.
Fixes CTS tests:
KHR-GL46.shading_language_420pack.binding_image_array
KHR-GL46.shading_language_420pack.length_of_compute_result