Rollup merge of #134432 - GuillaumeGomez:intra-doc-in-footnotes, r=notriddle

Fix intra doc links not generated inside footnote definitions

Fixes #132208.

The problem was that we were running the `Footnote` "pass" before the `LinkReplacer` one. Sadly, the change is bigger than it should because we can't specialize the `Iterator` trait implementation, forcing me to add a new type to handle the other `Iterator` kind (the one which still has the `Range`).

r? ``@notriddle``

Author: jieyouxu