bug#13618: 24.3.50; python-info-current-defun returns nil for a function without body

[Jorgen Schaefer]

Hello!
The `python-info-current-defun' function only works in functions and
methods that have a body, which is a bit confusing while writing code:

def foo():
    _|_

M-: (python-info-current-defun) => nil

def foo():
    a_|_

M-: (python-info-current-defun) => "foo"

class Test(object):
    def __init__(self):
        _|_

M-: (python-info-current-defun) => nil

class Test(object):
    def __init__(self):
        a_|_

M-: (python-info-current-defun) => "Test.foo"


Regards,
        -- Jorgen