Message2927

Please test the patch with the following test case files.
(1) test_sort.py
(2) test_builtin.py

test_sort.py is new and copied from Python-2.4.4/Lib/test/test_sort.py.
The following two test cases are excluded from the test run.
    del TestDecorateSortUndecorate.test_key_with_mutating_del
    del TestDecorateSortUndecorate.test_key_with_mutating_del_and_exception
because, user object is passed for "key" argument. That object has function
called __del__ that is mutating the data. It can't be checked as long as it
is invoked. I guess it needs some parsing effort before passing the object
to the sort.