Feature request: Expose "shouldVisitTemplateInstantiations" option in libclang (and the python bindings)

[trelau]

Hello,

I'm using libclang and the associated Python bindings to parse C++ headers and generate pybind11 source code. The library I am wrapping with Python makes heavy use of class templates and I was wondering if setting "shouldVisitTemplateInstantiations" to true would make the process easier. Perhaps an option in the libclang Python library (with default to false to keep current behavior)? This is the line in the c++ code I'd like to set to true from the Python bindings https://clang.llvm.org/doxygen/RecursiveASTVisitor_8h_source.html#l00167

[trelau]

Motivation: Today when I parse a class template instantiation I am unable to get any children from it like I would with a normal class definition (e.g., constructors, methods, etc.). To handle this I write a templated function that has Python bindings for the underlying template and I call it with the relevant template arguments and class name. This logically works but there are a bunch of edge cases that have to be handled and, I think, it would be a lot easier and robust to just treat a class template instantiation like a regular class when traversing the AST and making Python bindings.

If even setting this option to True wouldn't achieve the desired behavior, then this feature request is not as relevant.