tests,testlib: Add tests for gem5.runtime.get_runtime_isa()

Included in this patch are tests to be enabled once build/ALL/gem5.opt
has been introduced.

Change-Id: I4c7ddd366af07b6d8ba4edcbbf58a1cfc7a6cc56
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/57510
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
2 files changed