3dpong, vectoroids, teetertorture: fix darwin builds (#422140)

pkgs/by-name/po/pong3d/package.nix

···
 
   buildInputs = [ libX11 ];
 
-  makeFlags = [ "PREFIX=$(out)" ];
+  makeFlags = [
+    "PREFIX=$(out)"
+    "CC=${stdenv.cc.targetPrefix}cc" # fix darwin and cross-compiled builds
+  ];
 
   meta = {
     homepage = "http://www.newbreedsoftware.com/3dpong/";
     description = "One or two player 3d sports game based on Pong from Atari";
     license = lib.licenses.gpl2Plus;
-    platforms = lib.platforms.linux;
+    platforms = lib.platforms.unix;
   };
 })

pkgs/by-name/te/teetertorture/package.nix

···
     homepage = "http://www.newbreedsoftware.com/teetertorture/";
     description = "Simple shooting game with your cannon is sitting atop a teeter totter";
     license = lib.licenses.gpl2Plus;
-    platforms = lib.platforms.linux;
+    inherit (SDL.meta) platforms;
     mainProgram = "teetertorture";
   };
 }

pkgs/by-name/ve/vectoroids/package.nix

···
     description = "Clone of the classic arcade game Asteroids by Atari";
     mainProgram = "vectoroids";
     license = lib.licenses.gpl2Plus;
-    platforms = lib.platforms.linux;
+    inherit (SDL.meta) platforms;
   };
 }