[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:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.11
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by rwbarton):

 Are you sure about the version numbers? I see it working in 7.8, but
 failing in 7.10 and HEAD.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10747#comment:1>
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