flatcc: add two `-Wno-error` for compilation on gcc11 and later

pkgs/development/libraries/flatcc/default.nix

@@ -21,6 +21,11 @@ stdenv.mkDerivation rec {
     "-DCMAKE_BUILD_TYPE=Release"
   ];
 
+  NIX_CFLAGS_COMPILE = [
+    "-Wno-error=misleading-indentation"
+    "-Wno-error=stringop-overflow"
+  ];
+
   meta = {
     description = "FlatBuffers Compiler and Library in C for C ";
     homepage = "https://github.com/dvidelabs/flatcc";