Generate test failure output on abnormal termination - #1011

Thanks David! Why don't you add the noexcept back to the guid constructor that I removed here:

https://github.com/microsoft/cppwinrt/pull/1009/files

That will verify whether the CI build fails visibly or silently. Once that has been confirmed, just remove the noexcept again and it should be green again.

The log captures the failure but it doesn't fail the build itself.

It's worse than that - even normal test failures don't cause the pipeline to fail (see my latest commit in this PR and the corresponding run). I've sent email to the team to discuss.

Added some changes to reroute output to stderr when the test executable does not exit cleanly, and validated that this fails the pipeline with the noexcept in place as expected:

Logged #1012 on an unrelated test failure that passed on rerun (also passed on both x86 runs); this may have been masked for some time due to the lack of failure reporting in the build pipeline until now.