[GHC] #4378: Add IsString and Monoid instances for Doc

[GHC]

#4378: Add IsString and Monoid instances for Doc
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    Reporter:  basvandijk        |        Owner:              
        Type:  proposal          |       Status:  patch       
    Priority:  normal            |    Milestone:  Not GHC     
   Component:  libraries/pretty  |      Version:  6.12.3      
    Keywords:                    |     Testcase:              
   Blockedby:                    |   Difficulty:              
          Os:  Unknown/Multiple  |     Blocking:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
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Comment(by nominolo):

 Note that when this patch is applied the major version number must be
 bumped.  Quoting from the PVP:

   If any entity was removed, or the types of any entities or the
 definitions of datatypes or classes were changed, or '''instances were
 added''' or removed, then the new A.B must be greater than the previous
 A.B

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4378#comment:6>
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