config: Don't call sys.exit in interactive mode in run()

The run() method in Simulation.py used to call sys.exit() when the
simulator exits. This is undesirable when user has requested the
simulator to be run in interactive mode since it causes the simulator
to exit rather than entering the interactive Python environment.

configs/common/Simulation.py

@@ -507,4 +507,5 @@ def run(options, root, testsys, cpu_class):
     if options.checkpoint_at_end:
         m5.checkpoint(joinpath(cptdir, "cpt.%d"))
 
-    sys.exit(exit_event.getCode())
+    if not m5.options.interactive:
+        sys.exit(exit_event.getCode())