write_rtlil: add -sort to match old behavior

Author: widlarizer

backends/rtlil/rtlil_backend.cc

@@ -416,10 +416,14 @@ struct RTLILBackend : public Backend {
 		log("    -selected\n");
 		log("        only write selected parts of the design.\n");
 		log("\n");
+		log("    -sort\n");
+		log("        sort design in-place (used to be default).\n");
+		log("\n");
 	}
 	void execute(std::ostream *&f, std::string filename, std::vector<std::string> args, RTLIL::Design *design) override
 	{
 		bool selected = false;
+		bool do_sort = false;
 
 		log_header(design, "Executing RTLIL backend.\n");
 
@@ -430,12 +434,19 @@ struct RTLILBackend : public Backend {
 				selected = true;
 				continue;
 			}
+			if (arg == "-sort") {
+				do_sort = true;
+				continue;
+			}
 			break;
 		}
 		extra_args(f, filename, args, argidx);
 
 		log("Output filename: %s\n", filename.c_str());
 
+		if (do_sort)
+			design->sort();
+
 		*f << stringf("# Generated by %s\n", yosys_maybe_version());
 		RTLIL_BACKEND::dump_design(*f, design, selected, true, false);
 	}