semantic highlighting: distinguish nonlocals from locals

[bluss]

This is just a feature request or an idea, would it be possible to have a different highlighting class for nonlocals, so that they stand out clearly? I mean this in a general sense, not just those variables that are declared nonlocal.

def func():
    var = 1

    def inner(x):
        return x + var  # color x and var differently because var is not local