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

[GHC]

#10747: Infix pattern synonyms fail to parse (regression)
-------------------------------------+-------------------------------------
        Reporter:  heisenbug         |                Owner:  mpickering
            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):  Phab:D1295
-------------------------------------+-------------------------------------

Comment (by Austin Seipp <austin@…>):

 In [changeset:"69a6e4258786894578ffed2a1d907a74c52d779b/ghc"
 69a6e425/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="69a6e4258786894578ffed2a1d907a74c52d779b"
 Allow non-operator infix pattern synonyms

 For example

 ```
 pattern head `Cons` tail = head : tail
 ```

 Reviewed By: goldfire, austin

 Differential Revision: https://phabricator.haskell.org/D1295

 GHC Trac Issues: #10747
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10747#comment:10>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler