UseShorthandTypeNames incorrect with Sendable functions

[PeterAdams-A]

If I start with the code

var a: Optional< @Sendable (Int) -> (Float)> = nil

and apply swift-format format --parallel --recursive --in-place Sources version 509.0.0 the code becomes

var a: @Sendable (Int) -> (Float)? = nil

The optionalness has moved from the whole phrase to just the return type. This has a different meaning. The new code doesn't compile because of this.

[dnadoba]

This should be fixed with #589. However, the fix is only on main.
@allevato could we cut a release? Swift 5.9.1 and swift-syntax 509.0.1 was also released a couple days ago so this would be in line with them.

[allevato]

The fix in #589 only covered some/any type sugar, but didn't cover attributes. I'm working on a fix now along with some other open issues so that I can cut a 509.0.1 release with all of them.