Issue #26939: Merge 3.6.

diff --cc Lib/test/support/__init__.py
Simple merge

diff --cc Misc/NEWS
index 1a874982e291a52a8a628f2e32b26e391bbd41c1,a15bb9bf871f1985ea0d0a1287e5bc9149bd24b0..e0cb0b785a7037c33fa812e92bb3be21144f71de
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -567,18 -603,8 +567,21 @@@ Tools/Demo
  Tests
  -----
  
 +- Issue #28666: Now test.support.rmtree is able to remove unwritable or
 +  unreadable directories.
 +
 +- Issue #23839: Various caches now are cleared before running every test file.
 +
 +- Issue #26944: Fix test_posix for Android where 'id -G' is entirely wrong or
 +  missing the effective gid.
 +
 +- Issue #28409: regrtest: fix the parser of command line arguments.
 +
  - Issue #28217: Adds _testconsole module to test console input.
  
++- Issue #26939: Add the support.setswitchinterval() function to fix
++  test_functools hanging on the Android armv7 qemu emulator.
++
  
  What's New in Python 3.6.0 beta 1
  =================================