Remove &verify -y dependency, rely on ABC origin tracking

ABC now propagates origin mappings natively through optimization
passes via vOrigins (berkeley-abc/abc#487), so we no longer need
to run &verify -y and rewrite the output to reconstruct the mapping.

Keep &verify for correctness checking but without -y flag.

Co-developed-by: Claude Code v2.1.44 (claude-opus-4-6)

Author: robtaylor

passes/techmap/abc9_exe.cc

@@ -249,13 +249,10 @@ void abc9_module(RTLIL::Design *design, std::string script_file, std::string exe
 
 	abc9_script += stringf("; &ps -l; &write -n %s/output.aig", tempdir_name);
 	if (design->scratchpad_get_bool("abc9.verify")) {
-		if (dff_mode) {
+		if (dff_mode)
 			abc9_script += "; &verify -s";
-		} else {
-			abc9_script += "; &verify -y";
-			// Rewrite output to include "y" extension from verification
-			abc9_script += stringf("; &write -n %s/output.aig", tempdir_name);
-		}
+		else
+			abc9_script += "; &verify";
 	}
 	abc9_script += "; time";
 	abc9_script = add_echos_to_abc9_cmd(abc9_script);