Came across this while testing fix for #4579 (doesn't block): This breaks: ``` a: b c: d for d, e of f ``` As does two-value `for...in`: ``` a: b c: d for d, e in f ``` whereas the corresponding single-value `for`s don't: ``` a: b c: d for d of f a: b c: d for d in f ```
