pickle.py, load_int(): Match cPickle's just-repaired ability to unpickle

64-bit INTs on 32-bit boxes (where they become longs).  Also exploit that
int(str) and long(str) will ignore a trailing newline (saves creating a
new string at the Python level).

pickletester.py:  Simulate reading a pickle produced by a 64-bit box.

Lib/pickle.py

@@ -615,7 +615,11 @@ class Unpickler:
     dispatch[NONE] = load_none
 
     def load_int(self):
-        self.append(int(self.readline()[:-1]))
+        data = self.readline()
+        try:
+            self.append(int(data))
+        except ValueError:
+            self.append(long(data))
     dispatch[INT] = load_int
 
     def load_binint(self):