Rollup merge of #147027 - GuillaumeGomez:tyalias-disambiguator, r=lolbinarycat

Add new `tyalias` intra-doc link disambiguator

Fixes rust-lang/rust#146855.

Alternative to rust-lang/rust#146866.

This adds support for a new disambiguator: `tyalias`. I think it's common enough to have type aliases nowaday, so no reason to not be able to have a disambiguator for them.

cc ``@fmease``
r? lolbinarycat

Author: matthiaskrgr