Because fallible_collections pulls hashbrown 0.13, we also upgrade
hashlink to 0.8.2, which updates to that version as well. Those were the
last two uses of hashbrown 0.12, so we can update the fake hashbrown
0.12 to 0.13.
We could skip the upgrade of hashlink, but that would leave us with two
fake hashbrowns, and we'd hit https://github.com/rust-lang/cargo/issues/13405
Differential Revision: https://phabricator.services.mozilla.com/D209317
643347a670