cpu-simple: Use a local temporary for the PC in preExecute.

This avoids having to dynamically allocate and then free a temporary
when working with the pc in preExecute.

Change-Id: Ic86e23d0f0c7e786122a6024a154bb2907a6afcb
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52071
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
2 files changed