Entries in `tests/gem5/.testignore` which were ignoring insttest tests, were stating the host system as 'arch64' instead of 'aarch64'. This has been fixed. Change-Id: Ib90bd89e0544d225afc012fefca98db0ea2d8dd0 Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25845 Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Ayaz Akram <yazakram@ucdavis.edu> Maintainer: Jason Lowe-Power <jason@lowepower.com>