Some methods should left undefined on Object

[cflee]

Per Python docs 3.3.7 on the data model, for numeric types, "Methods corresponding to operations that are not supported by the particular kind of number implemented (e.g., bitwise operations for non-integral numbers) should be left undefined."

For illustration, we consider the Float type which doesn't support bitwise operations like <<. Given this test code:

self.assertCodeExecution("""
    x = 0.0
    try:
        y = x.__lshift__
    except Exception as err:
        print(err)
        print(type(err))
    """)

We obtain the following output from the test suite:

AssertionError: '===end of test===\n' != "'float' object has no attribute '__lshif[47 chars]==\n"
+ 'float' object has no attribute '__lshift__'
+ <class 'AttributeError'>
  ===end of test===
 : Global context

In CPython, there is an AttributeError just for accessing the attribute/method. In VOC, accessing works perfectly fine, it's only invoking the __lshift__() method that throws the AttributeError. This behavior is incorrect.