haskell.compiler.ghc865Binary: Disable "pie" hardening. See NixOS#129247

While this does not fix `ghc865Binary` with musl, it at least prevents
that the other, newer errors are shadowed (see NixOS#129247).

pkgs/development/compilers/ghc/8.6.5-binary.nix

@@ -152,6 +152,15 @@ stdenv.mkDerivation rec {
     done
   '';
 
+  # In nixpkgs, musl based builds currently enable `pie` hardening by default
+  # (see `defaultHardeningFlags` in `make-derivation.nix`).
+  # But GHC cannot currently produce outputs that are ready for `-pie` linking.
+  # Thus, disable `pie` hardening, otherwise `recompile with -fPIE` errors appear.
+  # See:
+  # * https://github.com/NixOS/nixpkgs/issues/129247
+  # * https://gitlab.haskell.org/ghc/ghc/-/issues/19580
+  hardeningDisable = lib.optional stdenv.targetPlatform.isMusl "pie";
+
   doInstallCheck = true;
   installCheckPhase = ''
     unset ${libEnvVar}