Auto merge of #117572 - RalfJung:addr_of, r=cuviper

update and clarify addr_of docs

This updates the docs to match rust-lang/reference#1387. Cc `@rust-lang/opsem`

`@chorman0773` not sure if you had anything else you wanted to say here, I'd be happy to get your feedback. :)

Fixes rust-lang/rust#114902, so Cc `@joshlf`

Author: bors