[flang] Use more generic overload for Operation in Traverse (#133305)

Currently there are two specific overloads: for unary operations, i.e.
`Operation<D, R, O>`, and binary ones `Operation<D, R, LO, RO>`.

This makes it impossible for a derived class to use a single overload to
handle all types of operations: `Operation<D, R, O...>`. Since the base
overloads need to be included in the derived class's scope, via `using
Base::operator()` either one of the specific overloads will always be a
better candidate than the more generic derived one.

```
class MyVisitor : public Traverse<...> {
  using Traverse<...>::operator();

  template <typename D, typename R, typename... O>
  Result operator()(const Operation<D, R, O...> &op) const {
    // Will never be used.
  }
};
```
This patch replaces the two specific overloads for Operation in Traverse
with a single generic overload, while preserving the existing
functionality, and allowing derived classes to use a single overload as
well.

0 files changed, 0 insertions, 0 deletions