[GHC] #9515: Deprecate -XExplicitForAll

[GHC]

#9515: Deprecate -XExplicitForAll
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              Reporter:  dfeuer      |            Owner:
                  Type:  feature     |           Status:  new
  request                            |        Milestone:
              Priority:  normal      |          Version:  7.8.3
             Component:  Compiler    |         Keywords:
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:
       Type of failure:              |  Related Tickets:
  None/Unknown                       |
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by kosmikus):

 If the idea is to avoid confusion, and the `ExplicitForall` flag is
 currently implied by others, then shouldn't `RankNTypes`,
 `LiberalTypeSynonyms`, and `ExistentialQuantification` all imply
 `ScopedTypeVariables` instead? But that's somewhat non-obvious ...

 I personally think that while the current situation is unfortunate, the
 proposed solution isn't ideal either. I'd keep everything as it currently
 is, until we get to a point where we can agree that `ScopedTypeVariables`
 should be enabled by default.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9515#comment:2>
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