Rollup merge of #147615 - jdonszelmann:span-calls-doc-attr, r=JonathanBrouwer,GuillaumeGomez

reduce calls to attr.span() in old doc attr parsing

r? `@oli-obk`

should be trivial, can also delegate to `@GuillaumeGomez` or `@JonathanBrouwer.`

As part of making span() return an option I want to reduce the number of places we call span in without it being known what specific attr it's for. This makes that more obvious for doc. Part of a chain of PRs that's coming.

rust-lang/rust#131229 (comment)

Author: matthiaskrgr