Blender Git Loki

Fix crash introduced in engine separation (50fb3ea3)

Basically DEG_OBJECT_ITER (or rather,
BKE_scene_layer_engine_settings_update) wasn't creating
Object->collection_settings data for invisible objects.

Now I'm removing those objects from the loop entirely. If we are to
bring them back we need to either create CollectionEngineSettings dat
from them or to skip them in DRW_mode_cache_populate.