[GHC] #9515: Deprecate -XExplicitForAll

[GHC]

#9515: Deprecate -XExplicitForAll
-------------------------------------+-------------------------------------
       Reporter:  dfeuer             |                   Owner:
           Type:  feature request    |                  Status:  new
       Priority:  normal             |               Milestone:
      Component:  Compiler           |                 Version:  7.8.3
       Keywords:                     |        Operating System:
   Architecture:  Unknown/Multiple   |  Unknown/Multiple
     Difficulty:  Unknown            |         Type of failure:
     Blocked By:                     |  None/Unknown
Related Tickets:                     |               Test Case:
                                     |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
 The problem is that it uses the same syntax as -XScopedTypeVariables to
 mean something a bit different, and incompatible. -XExplicitForAll is of
 rather limited utility, whereas -XScopedTypeVariables is a wonderful
 thing. Confusion is bad.

 {{{#!hs
 f :: forall a . a -> [a]
 f a = let g :: a -> a
           g x = x
       in g [a]
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9515>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler