time::Interval ticks during sleep on Windows but not on Linux

[mahkoh]

tokio/tokio/src/time/interval.rs

Lines 125 to 139 in 5e406a7

	fn poll_tick(&mut self, cx: &mut Context<'_>) -> Poll<Instant> {
	// Wait for the delay to be done
	ready!(Pin::new(&mut self.delay).poll(cx));
	// Get the `now` by looking at the `delay` deadline
	let now = self.delay.deadline();
	// The next interval value is `duration` after the one that just
	// yielded.
	let next = now + self.period;
	self.delay.reset(next);
	// Return the current instant
	Poll::Ready(now)
	}

This code is affected by rust-lang/rust#79462

[Darksonn]

Perhaps we should just add a line to the doc that we mirror std's behavior regarding sleep behavior, and what that behavior is at the time of writing.

[mahkoh]

This is not immediately connected to sleep. If tokio used a busy loop instead of sleeping, the difference in behavior would still be there. std::thread::sleep behaves the same way on windows and linux.