Merge pull request #125933 from NixOS/backport-125100-to-release-21.05

[Backport release-21.05] treesitter: include CXX headers compiling with clang Darwin

pkgs/development/tools/parsing/tree-sitter/grammar.nix

@@ -1,5 +1,7 @@
 { stdenv
 , tree-sitter
+, libcxx
+, lib
 }:
 
 # Build a parser grammar and put the resulting shared object in `$out/parser`
@@ -27,6 +29,7 @@ stdenv.mkDerivation {
       "${source}/${location}"
   ;
 
+  NIX_CFLAGS_COMPILE = lib.optionalString stdenv.isDarwin "-I${lib.getDev libcxx}/include/c++/v1";
   buildInputs = [ tree-sitter ];
 
   dontUnpack = true;