[GHC] #5743: Configurably use system-provided libffi

[GHC]

#5743: Configurably use system-provided libffi
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    Reporter:  nomeata           |       Owner:  trommler    
        Type:  feature request   |      Status:  new         
    Priority:  normal            |   Milestone:  7.6.1       
   Component:  Build System      |     Version:  7.2.1       
    Keywords:                    |          Os:  Linux       
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown
  Difficulty:  Unknown           |    Testcase:              
   Blockedby:                    |    Blocking:              
     Related:                    |  
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Comment(by slyfox):

 A note:

 what is missing in fedora/debian patch is:
 - the real request for libffi's library and include path via pkg-config.
 - ./configure time convigurability

 Gentoo, for example, allws multiple libffi headers in the following
 locations:
 /usr/lib64/libffi-3.0.11/include/ffi.h
 /usr/lib64/libffi-3.0.11/include/ffitarget.h

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5743#comment:5>
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