message: Fix warning for `memset` of non-trivial type in PathCache
  As suggested by the compiler, value-initialization is used instead.
diff: @@ -687,8 +687,7 @@ void PathNodePool::AllStates(unsigned frame, std::vector<void*>* stateVec)
  PathCache::PathCache(int _allocated)
  {
  - mem = new Item[_allocated];
  - memset(mem, 0, sizeof(*mem) * _allocated);
  + mem = new Item[_allocated]{};
  allocated = _allocated;
  nItems = 0;
  hit = 0;
  