ccl_device int bsdf_reflection_sample(ccl_private const ShaderClosure *sc, float3 Ng, float3 I, float3 dIdx, float3 dIdy, float randu, float randv, ccl_private float3 *eval, ccl_private float3 *omega_in, ccl_private float3 *domega_in_dx, ccl_private float3 *domega_in_dy, ccl_private float *pdf)