title: OpenCV __int128 error when compiling for 64 bit
body: <p>I tried to compile opencv for x86_64 and arm64-v8a, but it threw error below:</p>
  
  <pre><code>In file included 
  from D:\AndroidSDK\android-ndk-r17b\sources\cxx-stl\gnu-libstdc++\4.9\include/bits/stl_algo.h:59:0,
  from D:\AndroidSDK\android-ndk-r17b\sources\cxx-stl\gnu-libstdc++\4.9\include/algorithm:62,
  from D:\TMP\C++\OpenCV-Source\opencv-3.4.3\modules\core\include/opencv2/core/base.hpp:55,
  from D:\TMP\C++\OpenCV-Source\opencv-3.4.3\modules\core\include/opencv2/core.hpp:54,
  from D:\TMP\C++\OpenCV-Source\opencv-3.4.3\modules\core\include/opencv2/core/utility.hpp:56,
  from D:\TMP\C++\OpenCV-Source\opencv-3.4.3\modules\core\src\precomp.hpp:49,
  from D:\TMP\C++\OpenCV-Source\opencv-3.4.3\modules\core\src\algorithm.cpp:43:
  D:\AndroidSDK\android-ndk-r17b\sources\cxx-stl\gnu- 
  libstdc++\4.9\include/cstdlib:178:10: error: expected unqualified-id before 
  '__int128'
  inline __int128
  D:\AndroidSDK\android-ndk-r17b\sysroot\usr\include\aarch64-linux- 
  android/asm/sigcontext.h:40:3: error: '__uint128_t' does not name a type
  __uint128_t vregs[32];
  </code></pre>
  
  <p>How to solve it?</p>