Style and comments

* Added explanatory comments
* Pushed f64 to the top of the for loop body

mlir/parsers/qasm3/visitor_handlers/quantum_types_handler.cpp

@@ -152,11 +152,13 @@ antlrcpp::Any qasm3_visitor::visitQuantumGateDefinition(
   // from this custom gate definition
   std::vector<mlir::Value> result_qubit_vals;
   for (auto arg : entryBlock.getArguments()) {
-    mlir::Value last_user = arg;
+    // check if argument is a gate param
     if (arg.getType().isF64()) {
         result_qubit_vals.push_back(arg);
+    // skip use chain traversal
         continue;
     }
+    mlir::Value last_user = arg;
     auto users = last_user.getUsers();
 
     while (!users.empty()) {