add morphCell instead of type assignments, test_cell passes for all cells

passes/cmds/chformal.cc

@@ -46,7 +46,7 @@ static RTLIL::IdString formal_flavor(RTLIL::Cell *cell)
 static void set_formal_flavor(RTLIL::Cell *cell, RTLIL::IdString flavor)
 {
 	if (cell->type != ID($check)) {
-		cell->type = flavor;
+		cell = cell->module->morphCell(flavor, cell);
 		return;
 	}
 
@@ -423,7 +423,7 @@ struct ChformalPass : public Pass {
 					if (cell->getPort(ID::ARGS).empty()) {
 						module->remove(cell);
 					} else {
-						cell->type = ID($print);
+						cell = cell->module->morphCell(ID($print), cell);
 						cell->setPort(ID::EN, combined_en);
 						cell->unsetPort(ID::A);
 						cell->unsetParam(ID(FLAVOR));

passes/cmds/chtype.cc

@@ -70,12 +70,12 @@ struct ChtypePass : public Pass {
 			for (auto cell : module->selected_cells())
 			{
 				if (map_types.count(cell->type)) {
-					cell->type = map_types.at(cell->type);
+					cell = cell->module->morphCell(map_types.at(cell->type), cell);
 					continue;
 				}
 
 				if (set_type != IdString()) {
-					cell->type = set_type;
+					cell = cell->module->morphCell(set_type, cell);
 					continue;
 				}
 			}

passes/cmds/design.cc

@@ -318,7 +318,7 @@ struct DesignPass : public Pass {
 						done[cell->type] = trg_name;
 					}
 
-					cell->type = done.at(cell->type);
+					cell = cell->module->morphCell(done.at(cell->type), cell);
 				}
 			}
 		}

passes/cmds/dft_tag.cc

@@ -109,7 +109,7 @@ struct DftTagWorker {
 			module->remove(cell);
 		}
 		for (auto cell : original_cells) {
-			cell->type = ID($get_tag);
+			cell = cell->module->morphCell(ID($get_tag), cell);
 		}
 
 		if (design_changed)

passes/cmds/setattr.cc

@@ -220,7 +220,7 @@ struct SetparamPass : public Pass {
 		{
 			for (auto cell : module->selected_cells()) {
 				if (!new_cell_type.empty())
-					cell->type = new_cell_type;
+					cell = cell->module->morphCell(new_cell_type, cell);
 				do_setunset(cell->parameters, setunset_list);
 			}
 		}