message: use bufferarea for allocating buffer
diff: #include <opencv2/core/hal/hal.hpp>
  #include "opencv2/core/hal/intrin.hpp"
  +#include <opencv2/core/utils/buffer_area.private.hpp>
  namespace cv {
  @@ -167,23 +168,17 @@ float calcOrientationHist(
  int i, j, k, len = (radius*2+1)*(radius*2+1);
  float expf_scale = -1.f/(2.f * sigma * sigma);
  -#if CV_SIMD
  - AutoBuffer<float> bufX(len + v_float32::nlanes);
  - AutoBuffer<float> bufY(len + v_float32::nlanes);
  - AutoBuffer<float> bufO(len + v_float32::nlanes);
  - AutoBuffer<float> bufW(len + v_float32::nlanes);
  - AutoBuffer<float> bufT(n+4 + v_float32::nlanes);
  - float *X = alignPtr(bufX.data(), CV_SIMD_WIDTH);
  - float *Y = alignPtr(bufY.data(), CV_SIMD_WIDTH);
  - float *Mag = X;
  - float *Ori = alignPtr(bufO.data(), CV_SIMD_WIDTH);
  - float *W = alignPtr(bufW.data(), CV_SIMD_WIDTH);
  - float *temphist = alignPtr(bufT.data(), CV_SIMD_WIDTH)+2;
  -#else
  - AutoBuffer<float> buf(len*4 + n+4);
  - float *X = buf.data(), *Y = X + len, *Mag = X, *Ori = Y + len, *W = Ori + len;
  - float* temphist = W + len + 2;
  -#endif
  +
  + cv::utils::BufferArea area;
  + float *X = 0, *Y = 0, *Mag, *Ori = 0, *W = 0, *temphist = 0;
  + area.allocate(X, len, CV_SIMD_WIDTH);
  + area.allocate(Y, len, CV_SIMD_WIDTH);
  + area.allocate(Ori, len, CV_SIMD_WIDTH);
  + area.allocate(W, len, CV_SIMD_WIDTH);
  + area.allocate(temphist, n+4, CV_SIMD_WIDTH);
  + area.commit();
  + temphist += 2;
  + Mag = X;
  for( i = 0; i < n; i++ )
  temphist[i] = 0.f;
  