[GHC] #2968: add test for C trigraphs

[GHC]

#2968: add test for C trigraphs
------------------------------+---------------------------------------------
 Reporter:  duncan            |          Owner:                  
     Type:  task              |         Status:  new             
 Priority:  normal            |      Milestone:                  
Component:  Compiler          |        Version:  6.10.1          
 Severity:  normal            |     Resolution:                  
 Keywords:                    |       Testcase:                  
       Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
------------------------------+---------------------------------------------
Comment (by duncan):

 For info on gcc's treatment of trigraphs see
 http://gcc.gnu.org/onlinedocs/cpp/Initial-processing.html

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2968#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler