Index: llvm/include/llvm/ADT/StringMap.h
===================================================================
--- llvm/include/llvm/ADT/StringMap.h
+++ llvm/include/llvm/ADT/StringMap.h
@@ -119,6 +119,7 @@
     std::swap(NumBuckets, Other.NumBuckets);
     std::swap(NumItems, Other.NumItems);
     std::swap(NumTombstones, Other.NumTombstones);
+    std::swap(ItemSize, Other.ItemSize);
   }
 };