`-ast-print` drops namespace qualifier from conversion operator's target type

`clang -Xclang -ast-print` for:

```cpp
namespace ns_will_be_dropped {
template struct tp {
};
}
template auto f(T t) {
return t.operator ns_will_be_dropped::tp();
}
```

drops the namespace qualifier from the conversion operator's target type ([clang-22](https://godbolt.org/z/jWq19ehfs)):

```cpp
namespace ns_will_be_dropped {
template struct tp {
};
}
template auto f(T t) {
return t.operator tp(); // <-- no namespace here
}
```

The resulting code does not compile: [clang-22](https://godbolt.org/z/W3xajdKKa)

Start by running the reduced C++ example with clang -Xclang -ast-print and compare the printed conversion operator target type with the source. Trace the AST-printing path for conversion operators and templates; done means the namespace qualifier is retained and the printed result compiles.

Written by the indexing model from the issue text.