re2c: add patch for CVE-2020-11958

https://nvd.nist.gov/vuln/detail/CVE-2020-11958

pkgs/development/tools/parsing/re2c/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchFromGitHub, autoreconfHook }:
+{ stdenv, fetchFromGitHub, fetchpatch, autoreconfHook }:
 
 stdenv.mkDerivation rec {
   pname = "re2c";
@@ -11,6 +11,14 @@ stdenv.mkDerivation rec {
     sha256 = "0aqlf2h6i2m3dq11dkq89p4w4c9kp4x66s5rhp84gmpz5xqv1x5h";
   };
 
+  patches = [
+    (fetchpatch {
+      name = "CVE-2020-11958.patch";
+      url = "https://github.com/skvadrik/re2c/commit/c4603ba5ce229db83a2a4fb93e6d4b4e3ec3776a.patch";
+      sha256 = "1d95ahxk92g7k87sda9gxgmr3blyfzwd2y7h9jxj8zkd74knd9zh";
+    })
+  ];
+
   nativeBuildInputs = [ autoreconfHook ];
 
   doCheck = true;