harePackages: create subtree

This is a subtree for the (past, present and future) Hare language
infrastructure.

pkgs/development/compilers/hare/default.nix

@@ -0,0 +1,7 @@
+{ config, lib, pkgs }:
+
+lib.makeScope pkgs.newScope (self: with self; {
+
+  harec = callPackage ./harec { };
+  hare = callPackage ./hare { };
+})

pkgs/top-level/all-packages.nix

@@ -7211,8 +7211,8 @@ with pkgs;
     llvmPackages = llvmPackages_9;
   };
 
-  harec = callPackage ../development/compilers/hare/harec.nix { };
-  hare = callPackage ../development/compilers/hare/hare.nix { };
+  harePackages = recurseIntoAttrs (callPackage ../development/compilers/hare { });
+  inherit (harePackages) hare harec;
 
   ham = pkgs.perlPackages.ham;