ext,tests: Make return code based on test results

This patch also fixes a spelling mistake.

Change-Id: I8635216e512c10913a9cda54541d7e31e0d22a40
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17450
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

tests: Fix tests/main.py so it can be run from anywhere.

tests/main.py was trying to find paths relative to itself using the
string __name__ (which was __main__) when it should have been using the
string __file__ which holds the name of the file being executed.

Change-Id: I5ff4c42fc7d8b75ff6b96c3cde61baf731d84738
Reviewed-on: https://gem5-review.googlesource.com/c/15675
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

misc: updated shabang for python script

The default python on MacOS doesn’t have an alias to python2.
The official python version supported in gem5 is Python2.7.

This patch updates the shabang according to the version required in gem5.

Change-Id: I9533c0f7858b5b3cab0ef101be1ee5cd718105b0
Reviewed-on: https://gem5-review.googlesource.com/c/15375
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

tests,ext: Add a new testing library proposal

The new test library is split into two parts: The framework which resides
in ext/, and the gem5 helping components in /tests/gem5.

Change-Id: Ib4f3ae8d7eb96a7306335a3e739b7e8041aa99b9
Signed-off-by: Sean Wilson <spwilson2@wisc.edu>
Reviewed-on: https://gem5-review.googlesource.com/4421
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>