Given the persistent id code a shot at a class before calling save_global().

Some persistent picklers (well, probably, the *only* persistent
pickler) would like to pickle some classes in a special way.
diff --git a/Lib/pickle.py b/Lib/pickle.py
index e553920..a507595 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -213,6 +213,11 @@
         try:
             f = self.dispatch[t]
         except KeyError:
+            pid = self.inst_persistent_id(object)
+            if pid is not None:
+                self.save_pers(pid)
+                return
+
             try:
                 issc = issubclass(t, TypeType)
             except TypeError: # t is not a class
@@ -221,11 +226,6 @@
                 self.save_global(object)
                 return
 
-            pid = self.inst_persistent_id(object)
-            if pid is not None:
-                self.save_pers(pid)
-                return
-
             try:
                 reduce = dispatch_table[t]
             except KeyError: