Fix struct padding warning reported by MSVC (#613) When building on 32-bit x86.
diff --git a/include/ffi.h.in b/include/ffi.h.in
index 6cd19ba..0aa5b61 100644
--- a/include/ffi.h.in
+++ b/include/ffi.h.in
@@ -345,6 +345,9 @@ typedef struct {
ffi_cif *cif;
void (*fun)(ffi_cif*,void*,void**,void*);
void *user_data;
+#if defined(_MSC_VER) && defined(_M_IX86)
+ void *padding;
+#endif
} ffi_closure
#ifdef __GNUC__
__attribute__((aligned (8)))