Copy on write: Prevent crash when duplicating object with particle system

Transform system was using global main, which might have been pointing to a
freed scene layer.

source/blender/editors/transform/transform_conversions.c

@@ -5553,10 +5553,14 @@ static void set_trans_object_base_flags(TransInfo *t)
 	DEG_scene_relations_update(G.main, t->scene);
 
 	/* handle pending update events, otherwise they got copied below */
+	EvaluationContext eval_ctx;
+	DEG_evaluation_context_init_from_scene(&eval_ctx,
+	                                       t->scene, t->scene_layer,
+	                                       DAG_EVAL_VIEWPORT);
 	for (base = sl->object_bases.first; base; base = base->next) {
 		if (base->object->recalc & OB_RECALC_ALL) {
 			/* TODO(sergey): Ideally, it's not needed. */
-			BKE_object_handle_update(G.main->eval_ctx, t->scene, base->object);
+			BKE_object_handle_update(&eval_ctx, t->scene, base->object);
 		}
 	}