Allow TcDerivInfer to compile with GHC 8.0.1
authorBen Gamari <bgamari.foss@gmail.com>
Wed, 16 Aug 2017 23:01:59 +0000 (19:01 -0400)
committerBen Gamari <ben@smart-cactus.org>
Wed, 16 Aug 2017 23:02:28 +0000 (19:02 -0400)
commitb0ed07fafbe96c3eee6c7f41ef937973bedbf1dc
tree39453178a4c27703e0387a2edca3841862ef2b71
parenta8da0de27e600211f04601ac737c329d6603c700
Allow TcDerivInfer to compile with GHC 8.0.1

As of ed7a830de6a2ea74dd6bb81f8ec55b9fe0b52f28 this module uses
MultiWayIf, the parsing behavior of which changed in 8.0.2 due
to #10807. Reformat the code so that it compiles under both 8.0.1 and
8.0.2/8.2.1.

Test Plan: Validate bootstrapping with 8.0.1

Reviewers: austin

Subscribers: rwbarton, thomie, RyanGlScott

GHC Trac Issues: #14130

Differential Revision: https://phabricator.haskell.org/D3863
compiler/typecheck/TcDerivInfer.hs