feat: added zig loaders for unix and refactor

system-libs.nix

@@ -13,8 +13,8 @@ let
     '';
   };
 
-  bsd-toolchain = with pkgs.pkgsCross.x86_64-freebsd.buildPackages;
-    pkgs.writeText "bsd-toolchain.cmake" ''
+  freebsd-toolchain = with pkgs.pkgsCross.x86_64-freebsd.buildPackages;
+    pkgs.writeText "freebsd-toolchain.cmake" ''
       set(CMAKE_SYSTEM_NAME FreeBSD)
 
       set(CMAKE_C_COMPILER   ${clang}/bin/x86_64-unknown-freebsd-clang)
@@ -168,7 +168,7 @@ in {
       export CC=x86_64-unknown-freebsd-clang
       export CXX=x86_64-unknown-freebsd-clang++
       cmake \
-          -DCMAKE_TOOLCHAIN_FILE=${bsd-toolchain} \
+          -DCMAKE_TOOLCHAIN_FILE=${freebsd-toolchain} \
           -DCMAKE_BUILD_TYPE=MinSizeRel \
           -DBUILD_SHARED_LIBS=OFF \
           -DDISABLE_BLUETOOTH=ON \