Fix those parts in the testsuite that assumed that sys.maxint would cause overflow on x64.  Now the testsuite is well behaved on that platform.
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index baac252..3570ef1 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -2,7 +2,7 @@
 Common tests shared by test_str, test_unicode, test_userstring and test_string.
 """
 
-import unittest, string, sys
+import unittest, string, sys, struct
 from test import test_support
 from UserList import UserList
 
@@ -671,7 +671,7 @@
 
     def test_replace_overflow(self):
         # Check for overflow checking on 32 bit machines
-        if sys.maxint != 2147483647:
+        if sys.maxint != 2147483647 or struct.calcsize("P") > 4:
             return
         A2_16 = "A" * (2**16)
         self.checkraises(OverflowError, A2_16, "replace", "", A2_16)