Remove native popen() and fdopen(), replacing them with subprocess calls.
Fix a path to an assert in fileio_read().
Some misc tweaks.
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index d1c0f68..c98d61f 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -478,7 +478,7 @@
             [ '\r\n', input_lines ],
         ]
 
-        encodings = ('utf-8', 'bz2')
+        encodings = ('utf-8', 'latin-1')
 
         # Try a range of pad sizes to test the case where \r is the last
         # character in TextIOWrapper._pending_line.