False negative for undefined-variable when attempting to access class scope from comprehension

[anjsimmo]

Steps to reproduce

Consider the following example from the Python execution model reference here:

class A:
    a = 42
    b = list(a + i for i in range(10))

As per Python's documentation, executing this file will fail with the message NameError: name 'a' is not defined. (The class attribute a is considered out of scope from within the body of the generator expression. As of Python3, it would also be out of scope from within the body of a list comprehension.)

Current behavior

Pylint assumes that the class attribute a is visible from within the generator expression, and doesn't give a warning (i.e. a false negative).

Expected behavior

Pylint should print an undefined-variable warning when attempting to access class attributes from within the body of a generator expression or comprehension.

pylint --version output

pylint 2.4.4
astroid 2.3.3
Python 3.7.3 (default, Mar 27 2019, 22:11:17) 
[GCC 7.3.0]