message: global_heap: avoid adding an attached MiniHeap to a freelist
diff: @@ -171,6 +171,11 @@ public:
  }
  inline bool postFreeLocked(MiniHeap *mh, int sizeClass, size_t inUse) {
  + // its possible we raced between reading isAttached + grabbing a lock.
  + // just check here to avoid having to play whack-a-mole at each call site.
  + if (mh->isAttached()) {
  + return false;
  + }
  const auto currFreelistId = mh->freelistId();
  auto currFreelist = freelistFor(currFreelistId, sizeClass);
  const auto max = mh->maxCount();
  