[GHC] #10747: Infix pattern synonyms fail to parse (regression)

[GHC]

#10747: Infix pattern synonyms fail to parse (regression)
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        Reporter:  heisenbug         |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  7.10.3
       Component:  Compiler          |              Version:  7.10.1
  (Parser)                           |             Keywords:
      Resolution:                    |  PatternSynonyms
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
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Comment (by heisenbug):

 Maybe I have to enable `TypeOperators` too?

 ''<checking...>''

 No, same error message.
 {{{
 error: parse error on input ?`?
 Failed, modules loaded: none.
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10747#comment:5>
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