[compiler-rt] Augment `uncaught-exception.test` fuzzer test to be msvc-compatible (PR #125924)

[David Justo via llvm-commits]

davidmrdavid wrote:

My bad for the miss here. I'll work to test more thoroughly with clang proper and to monitor the failure reports (I did see the email, but found it unlikely this change would be to blame, I was wrong). Thanks for the quick fix here as well.

https://github.com/llvm/llvm-project/pull/125924