Rollup merge of #45649 - tbu-:pr_doc_bufread_eof, r=estebank
Rollup merge of #45649 - tbu-:pr_doc_bufread_eof, r=estebank

Add a hint what `BufRead` functions do on EOF

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