[llvm-branch-commits] [clang] release/21.x: [Clang][Cygwin] Use correct mangling rule (#158404) (PR #158442)

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https://github.com/jeremyd2019 approved this pull request.

LGTM, and this seems to be a regression from 20.x

https://github.com/llvm/llvm-project/pull/158442