SF patch #462296: Add attributes to os.stat results; by Nick Mathewson.

This is a big one, touching lots of files.  Some of the platforms
aren't tested yet.  Briefly, this changes the return value of the
os/posix functions stat(), fstat(), statvfs(), fstatvfs(), and the
time functions localtime(), gmtime(), and strptime() from tuples into
pseudo-sequences.  When accessed as a sequence, they behave exactly as
before.  But they also have attributes like st_mtime or tm_year.  The
stat return value, moreover, has a few platform-specific attributes
that are not available through the sequence interface (because
everybody expects the sequence to have a fixed length, these couldn't
be added there).  If your platform's struct stat doesn't define
st_blksize, st_blocks or st_rdev, they won't be accessible from Python
either.

(Still missing is a documentation update.)
diff --git a/pyconfig.h.in b/pyconfig.h.in
index fe8d262..0edfcb2 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -18,6 +18,15 @@
 /* Define to `int' if <sys/types.h> doesn't define.  */
 #undef gid_t
 
+/* Define if your struct stat has st_blksize.  */
+#undef HAVE_ST_BLKSIZE
+
+/* Define if your struct stat has st_blocks.  */
+#undef HAVE_ST_BLOCKS
+
+/* Define if your struct stat has st_rdev.  */
+#undef HAVE_ST_RDEV
+
 /* Define if your struct tm has tm_zone.  */
 #undef HAVE_TM_ZONE