This further abstracts the properties of registers so they can be removed from the CPUs. Change-Id: I2aa1bffe8b095a0301579e60270965c611d6db4e Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49694 Maintainer: Gabe Black <gabe.black@gmail.com> Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com> Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com> Tested-by: kokoro <noreply+kokoro@google.com>