[clang-tools-extra] [clang-doc] Precommit test for global variables (PR #145069)

[Erick Velez via cfe-commits]

evelez7 wrote:

### Merge activity

* **Jun 21, 6:55 PM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/145069).


https://github.com/llvm/llvm-project/pull/145069