llvm 14 lld: build with 2M stack size to fix firefox lto

pkgs/development/compilers/llvm/14/lld/default.nix

···
   cmakeFlags = lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
     "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
   ];
+  LDFLAGS = lib.optionalString stdenv.hostPlatform.isMusl "-Wl,-z,stack-size=2097152";
 
   outputs = [ "out" "lib" "dev" ];