nix-cl: provide the original pname as an attribute

Overrides often inherit pname from the overriden package, and if they
get the already-prefixed version, defaulting the systems list to [pname]
produces wrong (and unintuitive) results. So we keep the prefix in the
store paths for clarity, and nix-env sees disambiguated names with -i/-u
(which should not be used anyway); but overrides won't be broken.

pkgs/development/lisp-modules/nix-cl.nix

@@ -145,7 +145,7 @@ let
       ...
     } @ args:
 
-    stdenv.mkDerivation (rec {
+    (stdenv.mkDerivation (rec {
       inherit
         version nativeLibs javaLibs lispLibs systems asds
         pkg program flags faslExt
@@ -226,7 +226,14 @@ let
       meta = (args.meta or {}) // {
         maintainers = args.meta.maintainers or lib.teams.lisp.members;
       };
-    })));
+    })) // {
+      # Useful for overriding
+      # Overriding code would prefer to use pname from the attribute set
+      # However, pname is extended with the implementation name
+      # Moreover, it is used in the default list of systems to load
+      # So we pass the original pname
+      pname = args.pname;
+    }));
 
   # Build the set of lisp packages using `lisp`
   # These packages are defined manually for one reason or another: