[clang] [clang] Deduplicate the logic that only warns once when stack is almost full (PR #112552)

[Ilya Biryukov via cfe-commits]

https://github.com/ilya-biryukov approved this pull request.

LGTM, but please fix the comment from @cor3ntin before submitting about renaming the class

https://github.com/llvm/llvm-project/pull/112552