[GHC] #12493: Add gcoerceWith to Data.Type.Coercion

[GHC]

#12493: Add gcoerceWith to Data.Type.Coercion
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:  8.2.1
       Component:  libraries/base    |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2456
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * status:  new => patch
 * differential:   => Phab:D2456


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12493#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler