xrCore/xrMemory.h: allocate additional 16 bytes of memory for RELEASE

This will increase memory consumption a bit but I hope this should make
it more stable...

Well, will see if that's true.

src/xrCore/xrMemory.h

@@ -17,6 +17,14 @@
 
 class XRCORE_API xrMemory
 {
+    // Additional 16 bytes of memory almost like in original xr_aligned_offset_malloc
+    // But for DEBUG we don't need this if we want to find memory problems
+#ifdef DEBUG
+    constexpr size_t reserved = 0;
+#else
+    constexpr size_t reserved = 16;
+#endif
+
 public:
     xrMemory();
     void _initialize();
@@ -27,9 +35,9 @@ class XRCORE_API xrMemory
 public:
     size_t mem_usage();
     void   mem_compact();
-    inline void* mem_alloc             (size_t size) { stat_calls++; return scalable_malloc (     size); };
-    inline void* mem_realloc(void* ptr, size_t size) { stat_calls++; return scalable_realloc(ptr, size); };
-    inline void  mem_free   (void* ptr)              { stat_calls++;        scalable_free   (ptr);       };
+    inline void* mem_alloc             (size_t size) { stat_calls++; return scalable_malloc (     size + reserved); };
+    inline void* mem_realloc(void* ptr, size_t size) { stat_calls++; return scalable_realloc(ptr, size + reserved); };
+    inline void  mem_free   (void* ptr)              { stat_calls++;        scalable_free   (ptr);                  };
 };
 
 extern XRCORE_API xrMemory Memory;