There are couple of places where we do `foldUniqSet` just to
compute `any` or `all`. `foldUniqSet` is non-deterministic in the
general case and `any` and `all` also read nicer.

Test Plan: ./validate

Reviewers: simonmar, goldfire, simonpj, bgamari, austin

Reviewed By: simonpj

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2156

GHC Trac Issues: #4012