fix __packed attribute for MSVC (#646)
diff --git a/src/host/pico_platform/include/pico/platform.h b/src/host/pico_platform/include/pico/platform.h
index f415b12..27e5c08 100644
--- a/src/host/pico_platform/include/pico/platform.h
+++ b/src/host/pico_platform/include/pico/platform.h
@@ -27,8 +27,14 @@
#define __scratch_x(group)
#define __scratch_y(group)
+#ifndef _MSC_VER
#define __packed __attribute__((packed))
#define __packed_aligned __packed __attribute((aligned))
+#else
+// MSVC requires #pragma pack which isn't compatible with a single attribute style define
+#define __packed
+#define __packed_aligned
+#endif
#define __time_critical_func(x) x
#define __after_data(group)
