set __name__ in the root m5 script to __m5_main__ so we can

tell if the script is run from m5 as the m5 script

--HG--
extra : convert_revision : 06f646cbb8c82444ef345115aa49324a4d3a2c9f

src/python/m5/main.py

@@ -304,7 +304,8 @@ def main():
     sys.argv = arguments
     sys.path = [ os.path.dirname(sys.argv[0]) ] + sys.path
 
-    scope = { '__file__' : sys.argv[0] }
+    scope = { '__file__' : sys.argv[0],
+              '__name__' : '__m5_main__' }
 
     # we want readline if we're doing anything interactive
     if options.interactive or options.pdb: