[GHC] #16315: Pattern synonym implicit existential quantification

[GHC]

#16315: Pattern synonym implicit existential quantification
-------------------------------------+-------------------------------------
        Reporter:  int-index         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.6.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by goldfire):

 From the `Note [Pattern synonym existentials do not scope]`, it sounds
 like we aim to ''reject'' this code, not accept it. Do you find
 differently?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16315#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler