[clang] Reland: [clang][test] add testing for the AST matcher reference (PR #112168)

[Julian Schmidt via cfe-commits]

5chmidti wrote:

The last five commits are the cumulative changes for fixing the Buildbots. I will check in with the Buildbot owner to see if the previous issue has been solved by [4a85fa3](https://github.com/llvm/llvm-project/pull/112168/commits/4a85fa3594e3fea25b9d6e90f9c4a02054f7d05d)

https://github.com/llvm/llvm-project/pull/112168