base, sim: Adding support for message to GDB from python

Adding a small python function that allows to display
messages directly in GDB from the python interpreter.
This function is inside the Workload SimObject
(The stub is not a SimObject).
ex:
     system.workload.sendToGdb("message to display")

Change-Id: I46ddae079b10d298743e023f95bf15608f50e358
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/63531
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
5 files changed