Fix MMX on 32 bit x86.

test cases/common/139 simd/simd_mmx.c

@@ -44,7 +44,11 @@ void increment_mmx(float arr[4]) {
     __m64 packed = _mm_set_pi16(arr[3], arr[2], arr[1], arr[0]);
     __m64 incr = _mm_set1_pi16(1);
     __m64 result = _mm_add_pi16(packed, incr);
-    int64_t unpacker = _m_to_int64(result);
+    /* Should be
+     * int64_t unpacker = _m_to_int64(result);
+     * but it does not exist on 32 bit platforms for some reason.
+     */
+    int64_t unpacker = (int64_t)(result);
     _mm_empty();
     for(i=0; i<4; i++) {
       arr[i] = (float)(unpacker & ((1<<16)-1));