gnugo: pul patch pending upstream inclusion for -fno-common toolchain support

Without the change build on upstream gcc-10 fails as:

    ld: dfa.o:/build/gnugo-3.8/patterns/../engine/liberty.h:861: multiple definition of
      `meaningless_white_moves'; mkpat.o:/build/gnugo-3.8/patterns/../engine/liberty.h:861: first defined here
    ld: dfa.o:/build/gnugo-3.8/patterns/../engine/liberty.h:860: multiple definition of
      `meaningless_black_moves'; mkpat.o:/build/gnugo-3.8/patterns/../engine/liberty.h:860: first defined here

pkgs/games/gnugo/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl }:
+{ lib, stdenv, fetchurl, fetchpatch }:
 
 stdenv.mkDerivation rec {
   pname = "gnugo";
@@ -9,6 +9,16 @@ stdenv.mkDerivation rec {
     sha256 = "0wkahvqpzq6lzl5r49a4sd4p52frdmphnqsfdv7gdp24bykdfs6s";
   };
 
+  patches = [
+    # Pull patch pending upstream inclusion for -fno-common toolchain support:
+    #   https://savannah.gnu.org/patch/index.php?10208
+    (fetchpatch {
+      name = "fno-common.patch";
+      url = "https://savannah.gnu.org/patch/download.php?file_id=53240";
+      sha256 = "0s96qvmx244vq5pv2nzf7x863kq2y5skzjhbpyzaajfkldbj0sw4";
+    })
+  ];
+
   hardeningDisable = [ "format" ];
 
   meta = {