python: Move native wrappers to the _m5 namespace

Swig wrappers for native objects currently share the _m5.internal name
space with Python code. This is undesirable if we ever want to switch
from Swig to some other framework for native binding (e.g., PyBind11
or Boost::Python). This changeset moves all of such wrappers to the
_m5 namespace, which is now reserved for native code.

Change-Id: I2d2bc12dbc05b57b7c5a75f072e08124413d77f3
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

src/python/m5/trace.py

@@ -26,13 +26,5 @@
 #
 # Authors: Nathan Binkert
 
-import internal
-import util
-
-from internal.trace import output, ignore
-
-def disable():
-    internal.trace.disable()
-
-def enable():
-    internal.trace.enable()
+# Export native methods to Python
+from _m5.trace import output, ignore, disable, enable