use GCC's -Wpadded on DNA files, gives more useful warnings then makesdna.

source/blender/makesdna/DNA_curve_types.h

@@ -74,7 +74,7 @@ typedef struct Path {
 typedef struct BevList {
 	struct BevList *next, *prev;
 	int nr, dupe_nr;
-	short poly, hole;
+	int poly, hole;
 } BevList;
 
 /* These two Lines with # tell makesdna this struct can be excluded. */

source/blender/makesdna/intern/makesdna.c

@@ -1187,6 +1187,13 @@ int main(int argc, char **argv)
 }
 
 /* include files for automatic dependencies */
+
+/* extra safety check that we are aligned,
+ * warnings here are easier to fix the makesdna's */
+#ifdef __GNUC__
+#  pragma GCC diagnostic error "-Wpadded"
+#endif
+
 #include "DNA_listBase.h"
 #include "DNA_vec_types.h"
 #include "DNA_ID.h"