[GHC] #11370: Redundant superclass warnings being included in -Wall destroys the "3 Release Policy"

[GHC]

#11370: Redundant superclass warnings being included in -Wall destroys the "3
Release Policy"
-------------------------------------+-------------------------------------
        Reporter:  ekmett            |                Owner:  bgamari
            Type:  bug               |               Status:  patch
        Priority:  highest           |            Milestone:  8.0.1
       Component:  Compiler (Type    |              Version:  7.10.3
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  warning at compile-time            |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11369, #11429    |  Differential Rev(s):  Phab:D1956
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"2e49a31658afb4f730fcfec69edfc9e785af71f4/ghc"
 2e49a316/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="2e49a31658afb4f730fcfec69edfc9e785af71f4"
 DynFlags: Add -Wredundant-constraints to -Wall

 Test Plan: It works, I promise.

 Reviewers: austin

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D1956

 GHC Trac Issues: #11370
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11370#comment:35>
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