Fix implicit declaration of stat in mingw.

Author: SFE-Brudnerd

source/bmserial.c

@@ -28,8 +28,10 @@
 # include <io.h>
 # include <malloc.h>
 # if defined __MINGW32__ || defined __MINGW64__
+#   include <sys/stat.h>
 #   include "strlcpy.h"
 # elif defined _MSC_VER
+#   include <sys/stat.h>
 #   include "strlcpy.h"
 #   define access(p,m)       _access((p),(m))
 # endif