Rollup merge of #45610 - strake:atomic_from, r=nagisa
Rollup merge of #45610 - strake:atomic_from, r=nagisa

impl From<T> for AtomicT

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