[clang-tools-extra] [clang-doc] Add regression test for test comments in macros (PR #132510)

[Paul Kirth via cfe-commits]

ilovepi wrote:

>I am not familiar with PR, so accidentally closed the previous PR https://github.com/llvm/llvm-project/pull/132360. This is a new one.

You can remove this part from the description. It isn't relevant to the rest of the project, and doesn't belong in the commit log.

https://github.com/llvm/llvm-project/pull/132510