Fix some more Hydra evaluation errors

pkgs/development/libraries/haskell/accelerate-fft/default.nix

@@ -9,6 +9,6 @@ cabal.mkDerivation (self: {
     homepage = "https://github.com/AccelerateHS/accelerate-fft";
     description = "FFT using the Accelerate library";
     license = self.stdenv.lib.licenses.bsd3;
-    platforms = self.ghc.meta.platforms;
+    platforms = self.stdenv.lib.platforms.linux;
   };
 })

pkgs/development/libraries/haskell/cufft/default.nix

@@ -10,6 +10,6 @@ cabal.mkDerivation (self: {
     homepage = "http://github.com/robeverest/cufft";
     description = "Haskell bindings for the CUFFT library";
     license = self.stdenv.lib.licenses.bsd3;
-    platforms = self.ghc.meta.platforms;
+    platforms = self.stdenv.lib.platforms.linux;
   };
 })

pkgs/development/libraries/v8/default.nix

@@ -56,7 +56,7 @@ stdenv.mkDerivation {
 
     meta = with stdenv.lib; {
       description = "V8 is Google's open source JavaScript engine";
-      platforms = platforms.unix; 
+      platforms = platforms.linux ++ platforms.darwin;
       license = licenses.bsd3;
     };
 }