message: Fix Flann compilation under nvcc + NEON
  All <arm_neon.h> includes in core/cv_cpu_dispatch.h are protected by an
  ifndef __CUDACC__ to prevent attempting to use neon intrinsics when
  compiling cuda kernels (.cu) -- this prevents hard errors such as
  error: identifier "__builtin_neon_qi" is undefined
  Add this same protection to flann/dist.h to fix compilation involving
  flann.hpp.
diff: @@ -47,7 +47,7 @@ typedef unsigned __int64 uint64_t;
  # include <Intrin.h>
  #endif
  -#ifdef __ARM_NEON__
  +#if defined(__ARM_NEON__) && !defined(__CUDACC__)
  # include "arm_neon.h"
  #endif
  @@ -425,7 +425,7 @@ struct Hamming
  ResultType operator()(Iterator1 a, Iterator2 b, size_t size, ResultType /*worst_dist*/ = -1) const
  {
  ResultType result = 0;
  -#ifdef __ARM_NEON__
  +#if defined(__ARM_NEON__) && !defined(__CUDACC__)
  {
  uint32x4_t bits = vmovq_n_u32(0);
  for (size_t i = 0; i < size; i += 16) {
  