Closes #22205: sys._debugmallocstats is a cpython specific feature, so
test_debugmallocstats should be marked as such. Patch written by Martin
Matusiak.
Closes #22188: test_gdb now runs gdb with -nx: "Do not execute commands from
any .gdbinit initialization files".
backout changeset 3435c5865cfc due to buildbot failures. Ref #8797
Issue #22165: SimpleHTTPRequestHandler now supports undecodable file names.
Issue #22165: Fixed test_undecodable_filename on non-UTF-8 locales.
Issue #22201: Command-line interface of the zipfile module now correctly
extracts ZIP files with directory entries.  Patch by Ryan Wilson.
Issue #22068: Avoided reference loops with Variables and Fonts in Tkinter.
Issue #22165: Fixed test_undecodable_filename on Mac OS.
remove 2.2 and 2.6 compat code (closes #22200)

Patch from Thomas Kluyver.
Clean up test_user_command.