analyze: bad rewrite of derive(Clone)

[spernsteiner]

Input:

#[derive(Clone)]
struct Foo {
    x: i32,
}

Output:

#[derive(Foo)]
struct Foo {
    x: i32,
}

Notice derive(Clone) has been replaced with derive(Foo), which is bogus.

We previously had some logic to suppress rewrites coming from derive-generated functions, but this seems not to work any more.