[clang] [llvm] [clang][python][test] Move python binding tests to lit framework (PR #146844)

[Jannick Kremer via cfe-commits]

DeinAlptraum wrote:

We hit the 
> Invalid CXChildVisitResult!

assert in `CIndex.cpp`, which is marked `llvm_unreachable()`... the function covers all three variants of the `CXChildVisitResult` enum.

@Endilll I'm hitting supposedly unreachable code, only on this one platform apparently... if you have any idea why this is happening, I'd love to hear it. Note that the tests passed on the `clang-s390x-linux-multistage` runner. 

Reverted in #146931

https://github.com/llvm/llvm-project/pull/146844