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/__init__.py

@@ -32,15 +32,16 @@
 
 try:
     # Try to import something that's generated by swig
-    import internal.core
+    import _m5.core
 
     # Try to grab something from it in case demandimport is being used
-    internal.core.curTick
+    _m5.core.curTick
+    in_gem5 = True
 except ImportError:
-    # The import failed
-    internal = None
+    # The import failed, we're being called from the build system
+    in_gem5 = False
 
-if internal:
+if in_gem5:
     import SimObject
     import core
     import objects