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/debug.py

@@ -26,6 +26,8 @@
 #
 # Authors: Nathan Binkert
 
+from __future__ import print_function
+
 from UserDict import DictMixin
 
 import _m5.debug
@@ -34,25 +36,25 @@ from _m5.debug import schedBreak, setRemoteGDBPort
 from m5.util import printList
 
 def help():
-    print "Base Flags:"
+    print("Base Flags:")
     for name in sorted(flags):
         if name == 'All':
             continue
         flag = flags[name]
         children = [c for c in flag.kids() ]
         if not children:
-            print "    %s: %s" % (name, flag.desc())
-    print
-    print "Compound Flags:"
+            print("    %s: %s" % (name, flag.desc()))
+    print()
+    print("Compound Flags:")
     for name in sorted(flags):
         if name == 'All':
             continue
         flag = flags[name]
         children = [c for c in flag.kids() ]
         if children:
-            print "    %s: %s" % (name, flag.desc())
+            print("    %s: %s" % (name, flag.desc()))
             printList([ c.name() for c in children ], indent=8)
-    print
+    print()
 
 class AllFlags(DictMixin):
     def __init__(self):