Stabilize `nonzero_min_max`
## Overall
Stabilizes `nonzero_min_max` to allow the "infallible" construction of ordinary minimum and maximum `NonZero*` instances.
The feature is fairly straightforward and already matured for some time in stable toolchains.
```rust
let _ = NonZeroU8::MIN;
let _ = NonZeroI32::MAX;
```
## History
* On 2022-01-25, implementation was [created](https://github.com/rust-lang/rust/pull/93293).
## Considerations
* This report is fruit of the inanition observed after two unsuccessful attempts at getting feedback.
* Other constant variants discussed at https://github.com/rust-lang/rust/issues/89065#issuecomment-923238190 are orthogonal to this feature.
Fixes https://github.com/rust-lang/rust/issues/89065
ffc0b8a545