Try to fix RT #81529

[pplu]

I've written code to try to fix the case where you call throws_ok, the code doesn't die, and the test passes (RT#81529).

The test in t/Exception.t that doesn't throw ("throws_ok: normal exit matched") is failing due to this code change.

Just thought you'd like to consider this new behaviour, since the original (passing the test) is very confusing.