Fix gcc-6 build

- Include intrinsics polyfill in AVX512 vector binary micro-kernels

PiperOrigin-RevId: 285484657
diff --git a/src/f32-vbinary/vop-avx512f.c.in b/src/f32-vbinary/vop-avx512f.c.in
index 84594a3..e1816b3 100644
--- a/src/f32-vbinary/vop-avx512f.c.in
+++ b/src/f32-vbinary/vop-avx512f.c.in
@@ -12,6 +12,7 @@
 #include <immintrin.h>
 
 #include <xnnpack/common.h>
+#include <xnnpack/intrinsics-polyfill.h>
 #include <xnnpack/vbinary.h>