opencv: work around ld64 hardening issue (#538397)

pkgs/development/libraries/opencv/4.x.nix

@@ -89,6 +89,9 @@
 
   bzip2,
   callPackage,
+
+  # TODO: Clean up on `staging`.
+  llvmPackages,
 }@inputs:
 
 let
@@ -470,6 +473,10 @@ effectiveStdenv.mkDerivation {
   )
   ++ optionals enableCuda [
     cudaPackages.cuda_nvcc
+  ]
+  # TODO: Clean up on `staging`.
+  ++ optionals effectiveStdenv.hostPlatform.isDarwin [
+    llvmPackages.lld
   ];
 
   env = {
@@ -559,6 +566,10 @@ effectiveStdenv.mkDerivation {
   ]
   ++ optionals (enabledModules != [ ]) [
     (cmakeFeature "BUILD_LIST" (concatStringsSep "," enabledModules))
+  ]
+  # TODO: Clean up on `staging`.
+  ++ optionals effectiveStdenv.hostPlatform.isDarwin [
+    (cmakeFeature "CMAKE_LINKER_TYPE" "LLD")
   ];
 
   postBuild = optionalString enableDocs ''