`coreBindsSize` forced a ton of structure to stop space leaks.
Reid Barton has done some work recently to try to stop the leaks
at their source instead. Memory residency remains well below the
numbers Herbert posted on #13426 originally, but in some cases
a ways above the ones from 8.0. I need to figure out how to get
the numbers matched up to individual modules and do some
profiling.

Relates to #13426

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3606