Missing functionality in clang python binding

[ufolyah]

Our python project requires "clang_getUnqualifiedType" and "clang_getNonReferenceType" api in libclang, but they are not exported in python bindings.

Seems like the libclang python bindings have not been maintained for a long time, we hope it can catch up with the api listed in here

For now we have modified pylibclang code on our local machine and it works smoothly, so i think it would not be tough.