[GHC] #10820: Provide a way to detect what extensions are enabled via TH

[GHC]

#10820: Provide a way to detect what extensions are enabled via TH
-------------------------------------+-------------------------------------
        Reporter:  spinda            |                   Owner:  spinda
            Type:  feature request   |                  Status:  new
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Template Haskell  |                 Version:  7.10.2
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
                                     |  th/T18020.hs
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:  Phab:D1200
-------------------------------------+-------------------------------------
Changes (by spinda):

 * owner:   => spinda
 * testcase:   => th/T18020.hs
 * differential:   => Phab:D1200


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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10820#comment:5>
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