message: ubsan: Fix type mismatch in compact mode for document data
  We were misaligning document data on 64-bit platforms by placing 8b
  pointers at 4b offsets; fix this by reserving a full pointer worth of
  bytes for page marker.
diff: @@ -6875,7 +6875,8 @@ namespace pugi
  assert(!_root);
  #ifdef PUGIXML_COMPACT
  - const size_t page_offset = sizeof(uint32_t);
  + // space for page marker for the first page (uint32_t), rounded up to pointer size; assumes pointers are at least 32-bit
  + const size_t page_offset = sizeof(void*);
  #else
  const size_t page_offset = 0;
  #endif
  