This change adds assembly code for riscv pseudo instructions so that they can be used with riscv benchmarks. Change-Id: Ic979fd375e7750e92f52b900bf39e351f629fe2c Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38515 Reviewed-by: Jason Lowe-Power <power.jg@gmail.com> Reviewed-by: Gabe Black <gabe.black@gmail.com> Maintainer: Jason Lowe-Power <power.jg@gmail.com> Maintainer: Gabe Black <gabe.black@gmail.com> Tested-by: kokoro <noreply+kokoro@google.com>