haskellPackages.hashes: fix build on non-x86

Some hash implementations in hashes are platform-specific (32 vs 64
bit), but only implemented in terms of “is i686 or x86_64?”. This it'll
always fail on other platforms (like aarch64). Consequently it makes no
sense to build and execute the test suite there, even if some hash
implementations are platform independent and could be tested.

pkgs/development/haskell-modules/configuration-nix.nix

@@ -980,4 +980,11 @@ self: super: builtins.intersectAttrs super {
   # Test suite is just the default example executable which doesn't work if not
   # executed by Setup.hs, but works if started on a proper TTY
   isocline = dontCheck super.isocline;
+
+  # Some hash implementations are x86 only, but part of the test suite.
+  # So executing and building it on non-x86 platforms will always fail.
+  hashes = overrideCabal super.hashes {
+    doCheck = with pkgs.stdenv; hostPlatform == buildPlatform
+      && buildPlatform.isx86;
+  };
 }