Missing diagnostics for use of variables from parent function bodies

[TwitchBronBron]

BrightScript does not support closures, so we need to properly warn when referencing outer variables from inner functions.

In v1.0.0-alpha.39 there is no diagnostic for referencing outer in this example, but there should be.

function test(outer = 1)
    test2 = function(inner = 2)
        print outer + inner
    end function
end function