tests: Add tests for 'gem5.runtime.get_supported_isas'

Change-Id: I4224cca9384af48c1e090d9b34627cae8ce00715
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/60094
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
2 files changed