Started working on macOS platform layer.

platform_mac/mac_4ed.mm

@@ -0,0 +1,16 @@
+int
+main(int arg_count, char **args){
+    Thread_Context _tctx = {};
+    thread_ctx_init(&_tctx, ThreadKind_Main,
+                    get_base_allocator_system(),
+                    get_base_allocator_system());
+    
+    block_zero_struct(&global_mac_vars);
+    global_mac_vars.tctx = &_tctx;
+    
+    // NOTE(yuval): Application Core Update
+    Application_Step_Result result = {};
+    if (app.step != 0){
+        result = app.step(mac_vars.tctx, &target, base_ptr, &input);
+    }
+}