modeMemoryPool_t::reserve bug

[stgeke]

I think https://github.com/libocca/occa/blob/main/src/occa/internal/core/memoryPool.cpp#L131 should be changed to:

} else {
-       resize(reserved + alignedBytes);
+      resize(offset + alignedBytes);
      return slice(reserved, bytes);
}

[stgeke]

I was wrong. Current implementation is correct.

[stgeke]

Actually, there is an issue for the corner case size == reserved + alignedBytes.