Method mutable_data

cpp/src/arrow/compute/util_internal.h:80–80

 public:
  ~TempVectorHolder() { stack_->release(id_, num_elements_ * sizeof(T)); }
  T* mutable_data() { return reinterpret_cast<T*>(data_); }
  TempVectorHolder(TempVectorStack* stack, uint32_t num_elements) {
    stack_ = stack;
    num_elements_ = num_elements;