antlr3: make C++ headers compliant with C++20

(by stealing the relevant patch from Fedora)

pkgs/development/tools/parsing/antlr/3.5.nix

@@ -1,4 +1,4 @@
-{lib, stdenv, fetchurl, fetchFromGitHub, jre}:
+{lib, stdenv, fetchpatch, fetchurl, fetchFromGitHub, jre}:
 
 stdenv.mkDerivation rec {
   pname = "antlr";
@@ -14,6 +14,13 @@ stdenv.mkDerivation rec {
     sha256 = "1i0w2v9prrmczlwkfijfp4zfqfgrss90a7yk2hg3y0gkg2s4abbk";
   };
 
+  patches = [
+    (fetchpatch {
+      url = "https://src.fedoraproject.org/rpms/antlr3/raw/f1bb8d639678047935e1761c3bf3c1c7da8d0f1d/f/0006-antlr3memory.hpp-fix-for-C-20-mode.patch";
+      sha256 = "0apk904afjqbad6c7z9r72a9lkbz69vwrl8j2a6zgxjn8dfb2p8b";
+    })
+  ];
+
   installPhase = ''
     mkdir -p "$out"/{lib/antlr,bin,include}
     cp "$jar" "$out/lib/antlr/antlr-${version}-complete.jar"