Tracking issue for some Duration-taking functions

[alexcrichton]

This is a tracking issue for some small Duration-taking functions in the standard library, specifically the park_timeout and thread_sleep functions. Now that Duration is stabilized these are likely ready to be stable as-is.

[alexcrichton]

This feature is now entering its final comment period for stabilization.

[nagisa]

What do we do with the _ms variants? Deprecate or leave as is?

[alexcrichton]

Yeah we'd just deprecate them all in place

[SimonSapin]

Before we deprecate something #[stable] whose replacement has not reached the stable channel yet, I’d like to have a way to write libraries that build without warnings both on the stable and nightly channels. Perhaps opting out of deprecation warnings for specific items?

[aturon]

@SimonSapin We've talked about tying deprecation to particular versions, so that the warnings don't start until the relevant stable release (but it still shows as deprecated in rustdoc, etc).

For the time being, we can just do this manually by waiting to deprecate.

[SimonSapin]

@aturon Yes, either of these would work.