Fix for SST_ELI_DECLARE_NEW_BASE when BuilderInfo is a dependent …

…name. (#1006)

This is easier to describe with an example first. Imagine the following code:

```c++
template <class Component>
struct MyComponentBase : public Component {
    SST_ELI_DECLARE_NEW_BASE(Component, MyComponentBase);
    // tools that help us with SST::Component interfaces
};

struct MyComponent : MyComponentBase<SST::Component> {
    // A custom component
};

struct MyRouter : MyComponentBase<SST::Merlin::Router> {
    // A merlin router implementation
};
```

In this context, inside the `SST_ELI_DECLARE_NEW_BASE`, the `BuilderInfo` is a
dependent name in the `addDerivedInfo` template function, and can't be found
without qualification. The qualified name is `__LocalEliBase::BuilderInfo` and
it needs a `typename` pre-C++20.

This patch adds that typename to support this template pattern. This pattern
allows us to write utility code that can be injected into _any_ component
hierarchy.

src/sst/core/eli/elibase.h

@@ -187,6 +187,7 @@ class LoadedLibraries
     template <class __TT>                                                       \
     static bool addDerivedInfo(const std::string& lib, const std::string& elem) \
     {                                                                           \
+        using BuilderInfo = typename __LocalEliBase::BuilderInfo;               \
         return addInfo(lib, elem, new BuilderInfo(lib, elem, (__TT*)nullptr));  \
     }