flatbuffers: pull pending upstream fix for gcc-12 (#146930)

pkgs/development/libraries/flatbuffers/2.0.nix

@@ -1,6 +1,16 @@
-{ callPackage }:
+{ callPackage, fetchpatch }:
 
 callPackage ./generic.nix {
   version = "2.0.0";
   sha256 = "1zbf6bdpps8369r1ql00irxrp58jnalycc8jcapb8iqg654vlfz8";
+
+  patches = [
+    # Pull patch pending upstream inclustion for gcc-12 support:
+    #  https://github.com/google/flatbuffers/pull/6946
+    (fetchpatch {
+      name = "gcc-12.patch";
+      url = "https://github.com/google/flatbuffers/commit/17d9f0c4cf47a9575b4f43a2ac33eb35ba7f9e3e.patch";
+      sha256 = "0sksk47hi7camja9ppnjr88jfdgj0nxqxy8976qs1nx73zkgbpf9";
+    })
+  ];
 }