ghdl: use gnat11 to unbreak build (#184352)

{ stdenv, fetchFromGitHub, fetchpatch, callPackage, gnat, zlib, llvm, lib

{ stdenv, fetchFromGitHub, fetchpatch, callPackage, gnat11, zlib, llvm, lib

, backend ? "mcode" }:

assert backend == "mcode" || backend == "llvm";

  LIBRARY_PATH = "${stdenv.cc.libc}/lib";

  buildInputs = [ gnat zlib ] ++ lib.optional (backend == "llvm") [ llvm ];

  buildInputs = [ gnat11 zlib ] ++ lib.optional (backend == "llvm") [ llvm ];

  propagatedBuildInputs = lib.optionals (backend == "llvm") [ zlib ];

  preConfigure = ''