[clang-tools-extra] [clang-tidy] Fix identifier-naming style lookup in macro arguments (PR #206809)

[via cfe-commits]

savchart wrote:

I tried to make the test match the bug-triggering conditions as closely as possible. I added separate input files for the root config, the subdirectory config, and the macro definition. I also changed the config lookup to use the spelling location, which is the stricter policy here.

As a result, the test fails before the fix and passes after it.


https://github.com/llvm/llvm-project/pull/206809