Message5113

The relevant problem is in org.python.compiler.CodeCompiler#visitAssert:

        code.getstatic("org/python/core/Py", "AssertionError",
"Lorg/python/core/PyObject;");

We can't use this optimization to the standard builtin AssertionError,
instead it should be using getattr. Notably in CPython, this is possible
to do:

>>> import __builtin__
>>> del __builtin__.AssertionError
>>> assert 0
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: global name 'AssertionError' is not defined