Stop the simplifier from removing StaticPtr binds.
Summary: We have the FloatOut pass create exported ids for floated StaticPtr bindings. The simplifier doesn't try to remove those. This patch also improves on 7fc20b by making a common definition collectStaticPtrSatArgs to test for StaticPtr binds. Fixes #12207. Test Plan: ./validate Reviewers: simonpj, austin, bgamari, simonmar, goldfire Reviewed By: simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2366 GHC Trac Issues: #12207