Rustdoc search returns non working links related to #[doc(alias = "...")]

[kumbayo]

When searching for % https://doc.rust-lang.org/nightly/std/?search=%25
the search result shows std::ops::Rem::Rem
with a non working link to https://doc.rust-lang.org/nightly/std/ops/Rem/trait.Rem.html
(The same problem also happens for other aliases like ==, +=, ?, ...)

When searching for Rem https://doc.rust-lang.org/nightly/std/?search=Rem
the search result shows std::ops::Rem
with a working link to https://doc.rust-lang.org/nightly/std/ops/trait.Rem.html

Searching for aliases was implemented in #49757.
CC @GuillaumeGomez

Version reported by https://doc.rust-lang.org/nightly
Version 1.27.0-nightly (66363b2 2018-04-28)