Rollup merge of #44794 - napen123:master, r=frewsxcv
Rollup merge of #44794 - napen123:master, r=frewsxcv

Add doc example to HashMap::hasher

None

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