message: Remove unused variable (fix warning) NFC
diff: @@ -939,8 +939,7 @@ void PatternEmitter::createAggregateLocalVarsForOpArgs(
  "SmallVector<NamedAttribute, 4> tblgen_attrs; (void)tblgen_attrs;\n");
  for (int argIndex = 0, e = resultOp.getNumArgs(); argIndex < e; ++argIndex) {
  - if (const auto *attr =
  - resultOp.getArg(argIndex).dyn_cast<NamedAttribute *>()) {
  + if (resultOp.getArg(argIndex).is<NamedAttribute *>()) {
  const char *addAttrCmd = "if ({1}) {{"
  " tblgen_attrs.emplace_back(rewriter."
  "getIdentifier(\"{0}\"), {1}); }\n";
  