abc9.cc: Use -r for &dch

Avoids "ABC: The command has to terminate. Boxes are not in a topological order." error during `&if`.

Author: KrystalDelusion

passes/techmap/abc9.cc

@@ -38,8 +38,8 @@ struct Abc9Pass : public ScriptPass
 	Abc9Pass() : ScriptPass("abc9", "use ABC9 for technology mapping") { }
 	void on_register() override
 	{
-		RTLIL::constpad["abc9.script.default"] = "+&scorr; &sweep; &dc2; &dch -f; &ps; &if {C} {W} {D} {R} -v; &mfs";
-		RTLIL::constpad["abc9.script.default.area"] = "+&scorr; &sweep; &dc2; &dch -f; &ps; &if {C} {W} {D} {R} -a -v; &mfs";
+		RTLIL::constpad["abc9.script.default"] = "+&scorr; &sweep; &dc2; &dch -f -r; &ps; &if {C} {W} {D} {R} -v; &mfs";
+		RTLIL::constpad["abc9.script.default.area"] = "+&scorr; &sweep; &dc2; &dch -f -r; &ps; &if {C} {W} {D} {R} -a -v; &mfs";
 		RTLIL::constpad["abc9.script.default.fast"] = "+&if {C} {W} {D} {R} -v";
 		// Based on ABC's &flow
 		RTLIL::constpad["abc9.script.flow"] = "+&scorr; &sweep;" \