QEMU_PACKED: Remove gcc_struct attribute in Windows non x86 targets

This attribute is for x86 only, and it generates an warning on ARM64 Clang/MinGW targets. Signed-off-by: Cao Jiaxi <driver1998@foxmail.com> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

Author: driver1998

src/util.h

@@ -43,7 +43,7 @@
 #include <netinet/in.h>
 #endif
 
-#if defined(_WIN32)
+#if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__))
 #define SLIRP_PACKED __attribute__((gcc_struct, packed))
 #else
 #define SLIRP_PACKED __attribute__((packed))