make test_grammar pass with python -O

Lib/test/test_grammar.py

@@ -544,8 +544,10 @@ hello world
             assert 0, "msg"
         except AssertionError, e:
             self.assertEquals(e.args[0], "msg")
-        else:
-            self.fail("AssertionError not raised by assert 0")
+        # we can not expect an assertion error to be raised
+        # if the tests are run in an optimized python
+        #else:
+        #    self.fail("AssertionError not raised by assert 0")
 
     ### compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | funcdef | classdef
     # Tested below