[clang] Ast importer visitors (PR #138838)

[via cfe-commits]

ganenkokb-yandex wrote:

@balazske I've put some more fixes to patch to make it work. And now it is on top of main, and compiles with `-DBUILD_SHARED_LIBS=ON`

Full cmake command is:
`cmake -G Ninja -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;lld" -DLLVM_TARGETS_TO_BUILD="ARM" -DLLVM_DEFAULT_TARGET_TRIPLE="arm64-apple-darwin24.3.0" -DLLVM_BUILD_TESTS=ON  -DCLANG_BUILD_UNIT_TESTS=ON -DBUILD_SHARED_LIBS=ON ../llvm`

Can you make it a chance once more?

https://github.com/llvm/llvm-project/pull/138838