Rollup of 9 pull requests#83360

Merged

bors merged 24 commits intorust-lang:masterfrom

Dylan-DPC-zz:rollup-17xulpv

Mar 22, 2021

Commits on Jan 7, 2021

Make NonNull::as_ref (and friends) return refs with unbound lifetimes
thomcc
committed

Commits on Feb 26, 2021

Fix invalid slice access in String::retain
SkiFire13
committed

Commits on Mar 1, 2021

Move `std::sys::unix::platform` to `std::sys::unix::ext`
CDirkx
committed

Commits on Mar 4, 2021

slice: Stabilize IterMut::as_slice.
emilio
committed

Commits on Mar 5, 2021

stabilize feature(osstring_ascii)
fogti
committed

Commits on Mar 20, 2021

Commits on Mar 22, 2021