Build C sources with -fPIC when GHC is using dynamic libraries.
Build C sources with -fPIC when GHC is using dynamic libraries.

Fixes #2207.

randen/cabal,thomie/cabal,fugyk/cabal,lukexi/cabal,trskop/cabal,edsko/cabal,typelead/epm,sopvop/cabal,kolmodin/cabal,plumlife/cabal,bennofs/cabal,anton-dessiatov/cabal,themoritz/cabal,plow-technologies/cabal,gbaz/cabal,triplepointfive/cabal,garetxe/cabal,mightybyte/cabal,rimmington/cabal,lukexi/cabal,anton-dessiatov/cabal,ian-ross/cabal,plumlife/cabal,valderman/cabal,x-y-z/cabal,valderman/cabal,christiaanb/cabal,kolmodin/cabal,mmakowski/cabal,rimmington/cabal,garetxe/cabal,enolan/cabal,Peaker/cabal,mightybyte/cabal,x-y-z/cabal,martinvlk/cabal,headprogrammingczar/cabal,eric-stanley/cabal,corngood/cabal,Heather/cabal,Helkafen/cabal,triplepointfive/cabal,beni55/cabal,christiaanb/cabal,Peaker/cabal,themoritz/cabal,eric-stanley/cabal,bennofs/cabal,mydaum/cabal,thoughtpolice/cabal,enolan/cabal,ghc-android/cabal,ian-ross/cabal,mydaum/cabal,ghc-android/cabal,typelead/epm,gbaz/cabal,Heather/cabal,sopvop/cabal,Helkafen/cabal,kosmikus/cabal,gridaphobe/cabal,fugyk/cabal,thomie/cabal,mmakowski/cabal,seereason/cabal,beni55/cabal,trskop/cabal,kosmikus/cabal,thoughtpolice/cabal,themoritz/cabal,martinvlk/cabal,randen/cabal,sopvop/cabal,corngood/cabal,gridaphobe/cabal,edsko/cabal,plow-technologies/cabal,seereason/cabal,headprogrammingczar/cabal