Method get_memory

crates/c-api/tests/config.cc:86–90

    std::vector<uint8_t> storage;

    uint8_t *get_memory(size_t *byte_size, size_t *byte_capacity) {
      *byte_size = storage.size();
      *byte_capacity = storage.capacity();
      return &storage[0];
    }

    Result<std::monostate> grow_memory(size_t new_size) {
      storage.resize(new_size, 0);