Patch series to add to and imporve tests for CoreSight

[carsten . haitzler]

This improves how perf test handles finding shell scripts to run as
part of the testing allowing sub-directories, skipping files that
are not intentional shell script tests and then adds a set of tests
that improve what we cover for Arm CoreSight testing. The goal of
these tests is to expand the scenarios and data traced and examined
to track quality of trace data and improvements to that over time.

Eventually it'd be neater to break up the current Arm CoreSight tests
into smaller focused tests that share the same infrastructure, but
this here would be a first step.