scons: Switch from the print statement to the print function.

Starting with version 3, scons imposes using the print function instead
of the print statement in code it processes. To get things building
again, this change moves all python code within gem5 to use the
function version. Another change by another author separately made this
same change to the site_tools and site_init.py files.

Change-Id: I2de7dc3b1be756baad6f60574c47c8b7e80ea3b0
Reviewed-on: https://gem5-review.googlesource.com/8761
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/python/m5/util/__init__.py

@@ -39,6 +39,8 @@
 #
 # Authors: Nathan Binkert
 
+from __future__ import print_function
+
 import os
 import re
 import sys
@@ -57,26 +59,26 @@ from sorteddict import SortedDict
 # ever happen regardless of what the user does (i.e., an acutal m5
 # bug).
 def panic(fmt, *args):
-    print >>sys.stderr, 'panic:', fmt % args
+    print('panic:', fmt % args, file=sys.stderr)
     sys.exit(1)
 
 # fatal() should be called when the simulation cannot continue due to
 # some condition that is the user's fault (bad configuration, invalid
 # arguments, etc.) and not a simulator bug.
 def fatal(fmt, *args):
-    print >>sys.stderr, 'fatal:', fmt % args
+    print('fatal:', fmt % args, file=sys.stderr)
     sys.exit(1)
 
 # warn() should be called when the user should be warned about some condition
 # that may or may not be the user's fault, but that they should be made aware
 # of as it may affect the simulation or results.
 def warn(fmt, *args):
-    print >>sys.stderr, 'warn:', fmt % args
+    print('warn:', fmt % args, file=sys.stderr)
 
 # inform() should be called when the user should be informed about some
 # condition that they may be interested in.
 def inform(fmt, *args):
-    print >>sys.stdout, 'info:', fmt % args
+    print('info:', fmt % args, file=sys.stdout)
 
 class Singleton(type):
     def __call__(cls, *args, **kwargs):
@@ -166,14 +168,14 @@ def printList(items, indent=4):
     line = ' ' * indent
     for i,item in enumerate(items):
         if len(line) + len(item) > 76:
-            print line
+            print(line)
             line = ' ' * indent
 
         if i < len(items) - 1:
             line += '%s, ' % item
         else:
             line += item
-            print line
+            print(line)
 
 def readCommand(cmd, **kwargs):
     """run the command cmd, read the results and return them