message: core(ocl): workaround CL_OUT_OF_RESOURCES error
  Flush deallocation queue before calling map/unmap
diff: @@ -3613,11 +3613,12 @@ public:
  if (u->tempUMat())
  {
  CV_Assert(u->mapcount == 0);
  + flushCleanupQueue(); // workaround for CL_OUT_OF_RESOURCES problem (#9960)
  void* data = clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
  (CL_MAP_READ | CL_MAP_WRITE),
  0, u->size, 0, 0, 0, &retval);
  + CV_Assert(retval == CL_SUCCESS);
  CV_Assert(u->origdata == data);
  - CV_OclDbgAssert(retval == CL_SUCCESS);
  if (u->originalUMatData)
  {
  CV_Assert(u->originalUMatData->data == data);
  