Fix AVX2 dection

broken in 9cf12e92

configure.ac

@@ -691,13 +691,13 @@ AS_IF([test x"$enable_intrinsics" = x"yes"],[
            #include <time.h>
          ]],
          [[
-             unsigned char utest[16] = {1};
+             unsigned char utest[[16]] = {1};
              __m256 mtest;
-             __m256 mtest1;
-             __m256 mtest2;
+             __m256i mtest1;
+             __m256i mtest2;
              mtest = _mm256_set1_ps((float)time(NULL));
              mtest = _mm256_fmadd_ps(mtest, mtest, mtest);
-             mtest1 = _mm256_set_m128i(_mm_loadu_si64(utest));
+             mtest1 = _mm256_set_m128i(_mm_loadu_si64(utest), _mm_loadu_si64(utest));
              mtest2 =
               _mm256_cvtepi16_epi32(_mm_loadu_si128((__m128i_u *)utest));
              return _mm256_extract_epi16(_mm256_xor_si256(