[GHC] #657: add WARNING pragma

[GHC]

#657: add WARNING pragma
----------------------+-----------------------------------------------------
 Reporter:  ijones    |          Owner:  igloo      
     Type:  task      |         Status:  closed     
 Priority:  normal    |      Milestone:  6.10.1     
Component:  Compiler  |        Version:  6.4.1      
 Severity:  normal    |     Resolution:  fixed      
 Keywords:            |     Difficulty:  Easy (1 hr)
 Testcase:  N/A       |   Architecture:  Unknown    
       Os:  Unknown   |  
----------------------+-----------------------------------------------------
Changes (by igloo):

  * status:  new => closed
  * resolution:  => fixed

Comment:

 WARNING pragma added

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/657#comment:7>
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