While the PcCountTracker isn't necessary in the NULL ISA, the structure of the standard library requires us to have it built when running the replacement policy tests, which should fix these tests failing within the nightlies at the moment. Change-Id: I225b7923f2a11d351c24bdceba3ded4ed2b3bc87 Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/68597 Maintainer: Jason Lowe-Power <power.jg@gmail.com> Reviewed-by: Jason Lowe-Power <power.jg@gmail.com> Tested-by: kokoro <noreply+kokoro@google.com>