Occasionally gem5's stdout/stderr, when run within the TestLib framework, will be shuffled. This is resolved by flushing the stdout/stderr buffer before and after simulation. In addition to this, the verifier.py has been improved to remove boilerplate gem5 code from the stdout comparison. Change-Id: I04c8f9cee4475b8eab2f1ba9bb76bfa3cfcca6ec Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/34995 Reviewed-by: Jason Lowe-Power <power.jg@gmail.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Jason Lowe-Power <power.jg@gmail.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com> Tested-by: kokoro <noreply+kokoro@google.com>