[Python-ideas] Allow `return yield from`

(I originally wrote this in bpo47147, but apparently because it has to go through python-ideas first?) I would like to be able to use a `yield from` expression in a `return` statement without parentheses, as a small quality of life tweak, i.e.: return yield from gen instead of return (yield from gen) I think this makes sense, since `yield from` can be used on the right-hand-side of an assignment, which accepts any expression, and so should `return`. Here is a medium-sized real-world example of where I'm using this, where it would be nice to allow `return yield from`:https://gist.github.com/pxeger/48f97484364bf0b43dee974a8f0f4265 Patrick