Rollup merge of #76911 - RalfJung:vecdeque-aliasing, r=oli-obk
Rollup merge of #76911 - RalfJung:vecdeque-aliasing, r=oli-obk

fix VecDeque::iter_mut aliasing issues

Fixes https://github.com/rust-lang/rust/issues/74029

aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust