Added a new fileno() method.  ZODB's repozo.py wants this so it can
apply os.fsync() to the GzipFile backup files it creates.
diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py
index bb4ed49..81a4865 100644
--- a/Lib/test/test_gzip.py
+++ b/Lib/test/test_gzip.py
@@ -16,8 +16,16 @@
 /* See http://www.winimage.com/zLibDll for Windows */
 """
 
-f = gzip.GzipFile(filename, 'wb') ; f.write(data1 * 50) ; f.close()
+f = gzip.GzipFile(filename, 'wb') ; f.write(data1 * 50)
 
+# Try flush and fileno.
+f.flush()
+f.fileno()
+if hasattr(os, 'fsync'):
+    os.fsync(f.fileno())
+f.close()
+
+# Try reading.
 f = gzip.GzipFile(filename, 'r') ; d = f.read() ; f.close()
 verify(d == data1*50)