fix: add growth_left for dump and load, to fix the bug that when loading from a phmap which has a lot of deleted slots may cause further inserts to hang

parallel_hashmap/phmap.h

@@ -2283,6 +2283,8 @@ private:
 
     size_t& growth_left() { return std::get<0>(settings_); }
 
+    const size_t& growth_left() const { return std::get<0>(settings_); }
+
     template <size_t N,
               template <class, class, class, class> class RefSet,
               class M, class P, class H, class E, class A>

parallel_hashmap/phmap_dump.h

@@ -59,6 +59,7 @@ bool raw_hash_set<Policy, Hash, Eq, Alloc>::phmap_dump(OutputArchive& ar) const
         return true;
     ar.saveBinary(ctrl_,  sizeof(ctrl_t) * (capacity_ + Group::kWidth + 1));
     ar.saveBinary(slots_, sizeof(slot_type) * capacity_);
+    ar.saveBinary(&growth_left(), sizeof(size_t));
     return true;
 }
 
@@ -79,6 +80,7 @@ bool raw_hash_set<Policy, Hash, Eq, Alloc>::phmap_load(InputArchive& ar) {
         return true;
     ar.loadBinary(ctrl_,  sizeof(ctrl_t) * (capacity_ + Group::kWidth + 1));
     ar.loadBinary(slots_, sizeof(slot_type) * capacity_);
+    ar.loadBinary(&growth_left(), sizeof(size_t));
     return true;
 }