```
template <typename T> T func() { return T(); }
template int func<int>();
```
The second line is not currently represented in the AST, though is among the FunctionTemplateDecl's specializations (with `getTemplateSpecializationKind() == TSK_ExplicitInstantiationDefinition`(.
This patch simply adds it to the owning context, akin to how Class/Var template explicit instantiations are added to the owning context, and adjusts traversal to match that of CTSDs/VTSDs.
Not well tested.