Auto merge of #146013 - Jules-Bertholet:from-wrapper, r=Mark-Simulacrum

Add `From` impls for wrapper types





- ~`From<T: Copy> for ManuallyDrop<T>`~
- `From<T: UnwindSafe> for AssertUnwindSafe<T>`
- `From<T> for LazyCell<T, F>`
- `From<T> for LazyLock<T, F>`
- `From<T> for ThinBox<T>` (unstable)
- `From<T> for UniqueRc<T>` (unstable)
- `From<T> for UniqueArc<T>` (unstable)

@rustbot label T-libs-api needs-fcp

Also needs a crater run, as the insta-stable impls are technically breaking changes.

Author: bors