zig: move passthru into a separate file

pkgs/development/compilers/zig/generic.nix

@@ -142,28 +142,17 @@ stdenv.mkDerivation (finalAttrs: {
     runHook postInstallCheck
   '';
 
-  passthru = {
-    hook = callPackage ./hook.nix { zig = finalAttrs.finalPackage; };
-
-    bintools-unwrapped = callPackage ./bintools.nix { zig = finalAttrs.finalPackage; };
-    bintools = wrapBintoolsWith { bintools = finalAttrs.finalPackage.bintools-unwrapped; };
-
-    cc-unwrapped = callPackage ./cc.nix { zig = finalAttrs.finalPackage; };
-    cc = wrapCCWith {
-      cc = finalAttrs.finalPackage.cc-unwrapped;
-      bintools = finalAttrs.finalPackage.bintools;
-      extraPackages = [ ];
-      nixSupport.cc-cflags =
-        [
-          "-target"
-          "${stdenv.targetPlatform.system}-${stdenv.targetPlatform.parsed.abi.name}"
-        ]
-        ++ lib.optional (
-          stdenv.targetPlatform.isLinux && !(stdenv.targetPlatform.isStatic or false)
-        ) "-Wl,-dynamic-linker=${targetPackages.stdenv.cc.bintools.dynamicLinker}";
-    };
-
-    stdenv = overrideCC stdenv finalAttrs.finalPackage.cc;
+  passthru = import ./passthru.nix {
+    inherit
+      lib
+      stdenv
+      callPackage
+      wrapCCWith
+      wrapBintoolsWith
+      overrideCC
+      targetPackages
+      ;
+    zig = finalAttrs.finalPackage;
   };
 
   meta = {

pkgs/development/compilers/zig/passthru.nix

@@ -0,0 +1,33 @@
+{
+  lib,
+  stdenv,
+  zig,
+  callPackage,
+  wrapCCWith,
+  wrapBintoolsWith,
+  overrideCC,
+  targetPackages,
+}:
+{
+  hook = callPackage ./hook.nix { inherit zig; };
+
+  bintools-unwrapped = callPackage ./bintools.nix { inherit zig; };
+  bintools = wrapBintoolsWith { bintools = zig.bintools-unwrapped; };
+
+  cc-unwrapped = callPackage ./cc.nix { inherit zig; };
+  cc = wrapCCWith {
+    cc = zig.cc-unwrapped;
+    bintools = zig.bintools;
+    extraPackages = [ ];
+    nixSupport.cc-cflags =
+      [
+        "-target"
+        "${stdenv.targetPlatform.system}-${stdenv.targetPlatform.parsed.abi.name}"
+      ]
+      ++ lib.optional (
+        stdenv.targetPlatform.isLinux && !(stdenv.targetPlatform.isStatic or false)
+      ) "-Wl,-dynamic-linker=${targetPackages.stdenv.cc.bintools.dynamicLinker}";
+  };
+
+  stdenv = overrideCC stdenv zig.cc;
+}