[clang] [NFC][CFI] Dump test output to debug llvm-clang-win-x-aarch64 failure (PR #136002)

[Vitaly Buka via cfe-commits]

vitalybuka wrote:

We have output here: https://logs.chromium.org/logs/fuchsia/buildbucket/cr-buildbucket/8717401398964307329/+/u/clang/tests/stdout?format=raw

https://github.com/llvm/llvm-project/pull/136002