Auto merge of #149704 - matthiaskrgr:rollup-u4zhw99, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang/rust#146826 (Implement `Allocator` for `&mut A` where `A: Allocator + ?Sized`)
 - rust-lang/rust#148487 (add Option::into_flat_iter)
 - rust-lang/rust#148814 (stabilize `array_windows`)
 - rust-lang/rust#149401 (Fix `name()` functions for local defs in rustc_public)
 - rust-lang/rust#149683 (Fix armv8r-none-eabihf tier)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors