As of this change: https://gem5-review.googlesource.com/c/public/gem5/+/65051, the `_pre_instantiate` function must be called prior to `m5.instantiate` when using the stdlib without the Simulator module. Change-Id: Id5cec3b643d556b0f742719596abb53533b84cbd Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/65871 Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu> Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Jason Lowe-Power <power.jg@gmail.com> Maintainer: Bobby Bruce <bbruce@ucdavis.edu>