[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                     |
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Lemming):

 Replying to [comment:6 bgamari]:
 > > GHC-8.0 does not warn about any of these two. Should it?
 >
 > Indeed GHC 8.0 warns that the `a ~ b` constraint is redundant. This is
 arguably wrong and I've opened #11582 for this case. This is almost
 certainly not the last example of this sort that we will find.

 I just re-checked: ghci-8.0.0.20160214 warns with -fwarn-redundant-
 constraints but not with -Wall.
 That is, -fwarn-redundant-constraints is no longer part of -Wall? But this
 is the subject of this ticket.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10635#comment:7>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler