Bug 1574058 - Backout changeset c5acba2f11e0 (bug 1418425). r=froydnj

It was remaining from an earlier iteration of bug 1418425 that uses
zlib's crc32 function, but ended up unused because in the end it was
done differently.

Interestingly, the corresponding host objects are not built currently,
and actually fail to build when built manually (or with build system
changes that make them built).

Differential Revision: https://phabricator.services.mozilla.com/D42073

--HG--
extra : moz-landing-system : lando