Issue #20743: Fix a reference leak in test_tcl.
Issue #20750, Enable roundtrip tests for new 5-tuple untokenize. The
constructed examples and all but 7 of the test/test_*.py files (run with -ucpu)
pass. Remove those that fail the new test from the selection list.
Patch partly based on patches by G. Brandl (#8478) and G. Rees (#12691).
Issue #9974: When untokenizing, use row info to insert backslash+newline.
Original patches by A. Kuchling and G. Rees (#12691).
whitespace