Merge pull request #25190 from obsidiansystems/ios-stdenv-tiny-refactor

crossStdenv on iphone: Just get info from `targetPlatform`

pkgs/os-specific/darwin/ios-cross/default.nix

···
 , stdenv
 , coreutils
 , gnugrep
+, targetPlatform
 }:
 
 /* As of this writing, known-good prefix/arch/simulator triples:
···
  * x86_64-apple-darwin14  | x86_64 | true
  */
 
-{ prefix, arch, simulator ? false }: let
+let
+
+  prefix = targetPlatform.config;
+  inherit (targetPlatform) arch;
+  simulator = targetPlatform.isiPhoneSimulator or false;
+
   sdkType = if simulator then "Simulator" else "OS";
 
   sdkVer = "10.2";

pkgs/stdenv/cross/default.nix

···
     selfBuild = false;
     stdenv = if crossSystem.useiOSCross or false
       then let
-          inherit (buildPackages.darwin.ios-cross {
-              prefix = crossSystem.config;
-              inherit (crossSystem) arch;
-              simulator = crossSystem.isiPhoneSimulator or false; })
-            cc binutils;
+          inherit (buildPackages.darwin.ios-cross) cc binutils;
         in buildPackages.makeStdenvCross
           buildPackages.stdenv crossSystem
           binutils cc