benchmark

Fix broken PFM-enabled tests (#1623)

* Add pfm CI actions for bazel

* Fix problems in unit test.

* Undo enabling the CI tests for pfm - github CI machines seemingly do not support performance counters.

* Remove commented code - can be revisited in github history when needed, and there's a comment explaining the rationale behind the new test code.

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Co-authored-by: Andy Christiansen <achristiansen@google.com>
Co-authored-by: dominic <510002+dmah42@users.noreply.github.com>