Issue #22854: Merge UnsupportedOperation fixes from 3.5

diff --cc Lib/_pyio.py
Simple merge

diff --cc Lib/test/test_io.py
Simple merge

diff --cc Misc/NEWS
index 6b6d11caa39912be3d0f2f86d0043de3a521894d,e2e37a4064ad62beee6a2d258d4a6c848e899fff..64977018f66f316766ff26c29e2ff1bf9dbb0550
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -237,14 -98,10 +237,17 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #22854: Change BufferedReader.writable() and
+   BufferedWriter.readable() to always return False.
+ 
 +- Issue #26492: Exhausted iterator of array.array now conforms with the behavior
 +  of iterators of other mutable sequences: it lefts exhausted even if iterated
 +  array is extended.
 +
 +- Issue #26641: doctest.DocFileTest and doctest.testfile() now support
 +  packages (module splitted into multiple directories) for the package
 +  parameter.
 +
  - Issue #25195: Fix a regression in mock.MagicMock. _Call is a subclass of
    tuple (changeset 3603bae63c13 only works for classes) so we need to
    implement __ne__ ourselves.  Patch by Andrew Plummer.

diff --cc Modules/_io/bufferedio.c
Simple merge

diff --cc Modules/_io/iobase.c
Simple merge