Add overload for Relational<SomeType>

Author: kparzysz

flang/include/flang/Evaluate/tools.h

@@ -1418,6 +1418,8 @@ template <int Kind> Operator OperationCode(const LogicalOperation<Kind> &op) {
   return Operator::Unknown;
 }
 
+Operator OperationCode(const Relational<SomeType> &op);
+
 template <typename T> Operator OperationCode(const Relational<T> &op) {
   switch (op.opr) {
   case common::RelationalOperator::LT:

flang/lib/Evaluate/tools.cpp

@@ -1793,6 +1793,10 @@ std::string operation::ToString(operation::Operator op) {
   llvm_unreachable("Unhandler operator");
 }
 
+operation::Operator operation::OperationCode(const Relational<SomeType> &op) {
+  return common::visit([](auto &&s) { return OperationCode(s); }, op.u);
+}
+
 operation::Operator operation::OperationCode(const ProcedureDesignator &proc) {
   Operator code{llvm::StringSwitch<Operator>(proc.GetName())
           .Case("associated", Operator::Associated)