[GHC] #15334: (forall x. c x, forall x. d x) is not equivalent to forall x. (c x, d x)

[GHC]

#15334: (forall x. c x, forall x. d x) is not equivalent to forall x. (c x, d x)
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  merge
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler (Type    |              Version:  8.5
  checker)                           |             Keywords:
      Resolution:                    |  QuantifiedConstraints
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  GHC rejects       |            Test Case:  quantified-
  valid program                      |  constraints/T15334
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 Ryan, how important is this to you? While it is possible to backport this
 to 8.6, I suspect it will be quite a bit of work. The commit in comment:10
 appears to depend quite heavily on
 45f44e2c9d5db2f25c52abb402f197c20579400f which is a 1 kLoC refactoring
 which seems to have a slew of dependencies of its own. Unless this is
 breaking code in the wild I think it would be best to punt this to 8.8.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15334#comment:12>
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