Rustfmt breaks trait method when where clause is commented out

[vallentin]

In short, if you comment out the where clause, then the subsequent semicolon is moved into the comment.

Which of course breaks the code.

Before:

trait Foo {
    fn bar(&self)
    // where
    //     Self: Bar
    ;
}

After:

trait Foo {
    fn bar(&self)
    // where
    //     Self: Bar;
}

---

rustfmt 1.4.25-stable (0f29ff6 2020-11-11)