Joachim Breitner authored Jan 23, 2016 and Ben Gamari committed Jan 23, 2016

it seems that this closure type has not been in use since 5d52d9, so all
this is dead and untested code. This removes it. Some of the code might
be useful for a counting indirection as described in #10613, so when
implementing that, have a look at what this commit removes.

Test Plan: validate on harbormaster

Reviewers: austin, bgamari, simonmar

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1821