Some Cava optimization

• Optimize Cava's CPU schedule.
• Add fork-fusion pass for fusing unrelated but adjacent fork-joins.
• Add intrinsic functions to math expressions.
• Add print pass for debugging schedules.
• Avoid some edges in dot output to help little xdot out.
• TODO: need more relaxed bounds for forkify to parallelize demosaic.

hercules_opt/src/fork_transforms.rs

@@ -971,7 +971,7 @@ pub fn chunk_fork_unguarded(
                 let inner = DynamicConstant::div(new_factors[dim_idx], tile_size);
                 new_factors.insert(dim_idx, tile_size);
                 let inner_dc_id =  edit.add_dynamic_constant(inner);
-
+                new_factors[dim_idx + 1] = inner_dc_id;
         
                 let new_fork = Node::Fork {
                     control: old_control,