Fix XCode internal error workaround
@@ -1167,7 +1167,7 @@ ASTCENC_SIMD_INLINE vint4 interleave_rgba8(vint4 r, vint4 g, vint4 b, vint4 a)
{
// Workaround an XCode compiler internal fault; note is slower than slli_epi32
// so we should revert this when we get the opportunity
-#if __APPLE__
+#if defined(__APPLE__)
__m128i value = r.m;
value = _mm_add_epi32(value, _mm_bslli_si128(g.m, 1));
value = _mm_add_epi32(value, _mm_bslli_si128(b.m, 2));
