ghc-7.10.x: compile Setup.hs with -threaded to avoid hanging test suites

Closes https://github.com/NixOS/nixpkgs/issues/6259.

pkgs/development/haskell-modules/configuration-ghc-7.10.x.nix

@@ -62,10 +62,6 @@ self: super: {
   # bos/attoparsec#92
   attoparsec = dontCheck super.attoparsec;
 
-  # test suite hangs silently for at least 10 minutes
-  ChasingBottoms = dontCheck super.ChasingBottoms;
-  split = dontCheck super.split;
-
   # Test suite fails with some (seemingly harmless) error.
   # https://code.google.com/p/scrapyourboilerplate/issues/detail?id=24
   syb = dontCheck super.syb;
@@ -79,10 +75,6 @@ self: super: {
   # Version 1.19.5 fails its test suite.
   happy = dontCheck super.happy;
 
-  # Test suite hangs silently without consuming any CPU.
-  # https://github.com/ndmitchell/extra/issues/4
-  extra = dontCheck super.extra;
-
   # Test suite fails in "/tokens_bytestring_unicode.g.bin".
   alex = dontCheck super.alex;
 

pkgs/development/haskell-modules/generic-builder.nix

@@ -88,6 +88,7 @@ let
   setupCompileFlags = [
     (optionalString (!coreSetup) "-${packageDbFlag}=$packageConfDir")
     (optionalString (versionOlder "7.8" ghc.version) "-j$NIX_BUILD_CORES")
+    (optionalString (versionOlder "7.10" ghc.version) "-threaded") # https://github.com/haskell/cabal/issues/2398
   ];
 
   isHaskellPkg = x: (x ? pname) && (x ? version) && (x ? env);