Phil de Joux authored Jan 20, 2017 and Ben Gamari committed Jan 20, 2017

This fixes #12441, where definitions in a Haskell module and its boot
file which differed only in their quantifiers produced a confusing error
message. Here we teach GHC to always show quantifiers for these errors.

Reviewers: goldfire, simonmar, erikd, austin, hvr, bgamari

Reviewed By: bgamari

Subscribers: snowleopard, simonpj, mpickering, thomie

Differential Revision: https://phabricator.haskell.org/D2734

GHC Trac Issues: #12441