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

[Jannick Kremer via llvm-commits]

DeinAlptraum wrote:

I couldn't reproduce the issue when cross-compiling for s390x with my system GCC (15.1.1):
```bash
cmake -G Ninja -B build -S llvm -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ \
    -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_ASSERTIONS=True \
    '-DLLVM_LIT_ARGS='"'"'-v -j4'"'"'' -DLLVM_CCACHE_BUILD=OFF \
    -DLLVM_ENABLE_ASSERTIONS=ON '-DLLVM_ENABLE_PROJECTS=llvm;clang-tools-extra;clang' \
    -DLLVM_ENABLE_RUNTIMES=compiler-rt -DLLVM_DEFAULT_TARGET_TRIPLE=s390x-unknown-linux-gnu
```

So I'm starting a new attempt at #148802, with s390x marked as `UNSUPPORTED`

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