[GHC] #10635: -fwarn-redundant-constraints should not be part of -Wall

[GHC]

#10635: -fwarn-redundant-constraints should not be part of -Wall
-------------------------------------+-------------------------------------
        Reporter:  Lemming           |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  7.11
  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:  #9939, #9973,     |  Differential Rev(s):
  #10100, #10183, #11370             |
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Lemming):

 Replying to [comment:15 acfoltzer]:

 > I also wonder if it might make sense to distinguish between certain
 types of redundancy: for example, in our code a redundancy arising from a
 superclass relationship (e.g., `(Functor f, Applicative f)`) is almost
 always something we want to fix, but unused classes are almost always an
 API design choice rather than a bug we wish to avoid.
 >
 > I'm not sure where mboes' example falls between these cases, but maybe
 distinguishing the two cases and only including the superclass redundancy
 in `-Wall` could make folks happier?

 I would prefer that.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10635#comment:16>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler