Auto merge of #41071 - alexcrichton:beta-next, r=alexcrichton
[beta] Backport accepted nominations
This is a backport of
* https://github.com/rust-lang/rust/pull/40813
* https://github.com/rust-lang/rust/pull/40849
This also includes https://github.com/rust-lang/rust/pull/41069
Finally, this includes a bump to beta .3.
This is all current nominations except https://github.com/rust-lang/rust/pull/40863, which is not passing tests yet.