typo in std::thread::sleep

[vn971]

The documentation says: https://doc.rust-lang.org/std/thread/fn.sleep.html

... function will not return early due to a signal being received or a spurious wakeup.

Is that a typo? The function CAN return early right? (due to the reasons outlined)

I can make a fixing PR after confirmation.
UPD: Made a PR as well.

[dtolnay]

Let's continue with the improvements in #54646, but based on #54646 (comment) this sentence was accurate.