Rollup merge of #140511 - mathisbot:master, r=dtolnay

Stabilize `#![feature(non_null_from_ref)]`

This PR stabilizes the following:
```rust
impl<T: ?Sized> NonNull<T> {
    pub const fn from_ref(reference: &T) -> NonNull<T>;
    pub const fn from_mut(reference: &mut T) -> NonNull<T>;
}
```
The feature is tracked in [#130823](rust-lang/rust#130823).

Author: fmease