[GHC] #3853: make tags work in the new build system

[GHC]

#3853: make tags work in the new build system
---------------------------------+------------------------------------------
    Reporter:  igloo             |        Owner:  igloo       
        Type:  task              |       Status:  new         
    Priority:  normal            |    Milestone:  6.12 branch 
   Component:  Build System      |      Version:  6.12.1      
    Keywords:                    |   Difficulty:              
          Os:  Unknown/Multiple  |     Testcase:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
---------------------------------+------------------------------------------
 Make tags work in the new build system.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3853>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler