Nonlocal test fails

[MikhailArkhipov]

This is b/c in

def f():
    x = None
    y = None
    def g():
        nonlocal x, y
        x = 123
        y = 234
    return x, y

definitions of x come as x = 123 and x = None and we drop the outer one. PyCharm actually points to definition in nonlocal x. So we should figure out that x is nonlocal and either point to the nonlocal line or to x = None.

[MikhailArkhipov]

N/A after #546