Uninitialized scalar field

The field will contain an arbitrary value left over from earlier computations. A scalar field is not initialized by the constructor
/src/mongo/db/query/classic_plan_cache.h:272: UNINIT_CTOR 147900 Class member declaration for "solutionHash".
/src/mongo/db/query/classic_plan_cache.h:228: UNINIT_CTOR 147900 Non-static class member "solutionHash" is not initialized in this constructor nor in any functions that it calls.