cmd. core: save preimages on genesis creation (ethereum#25538)

force preimage dump for genesis

core/genesis.go

@@ -104,7 +104,7 @@ func (ga *GenesisAlloc) deriveHash() (common.Hash, error) {
 // all the generated states will be persisted into the given database.
 // Also, the genesis state specification will be flushed as well.
 func (ga *GenesisAlloc) flush(db ethdb.Database) error {
-	statedb, err := state.New(common.Hash{}, state.NewDatabase(db), nil)
+	statedb, err := state.New(common.Hash{}, state.NewDatabaseWithConfig(db, &trie.Config{Preimages: true}), nil)
 	if err != nil {
 		return err
 	}