Port actor creation to use direct calls (#6375)

python/ray/actor.py

@@ -6,7 +6,6 @@ import copy
 import inspect
 import logging
 import six
-import sys
 import weakref
 
 from abc import ABCMeta, abstractmethod
@@ -815,7 +814,11 @@ def exit_actor():
         ray.disconnect()
         # Disconnect global state from GCS.
         ray.state.state.disconnect()
-        sys.exit(0)
+        # Set a flag to indicate this is an intentional actor exit. This
+        # reduces log verbosity.
+        exit = SystemExit(0)
+        exit.is_ray_terminate = True
+        raise exit
         assert False, "This process should have terminated."
     else:
         raise Exception("exit_actor called on a non-actor worker.")