Rollup merge of #150883 - improve-deprecated-intra-doc-span, r=camelid

Improve span for "unresolved intra doc link" on `deprecated` attribute

Follow-up of rust-lang/rust#150721.

To make this work, I replaced the `Symbol` by an `Ident` to keep the `Span` information.

cc @folkertdev
r? @camelid

Author: JonathanBrouwer