Issue #14794: slice.indices no longer returns OverflowError for out-of-range start, stop, step or length.

Check if data is decoded by os.fsdecode() (filesystem encoding with
surrogateescape error handler, PEP 383), not by UTF-8 or the filesystem
encoding in strict mode.

Use TESTFN_UNDECODABLE in test_cmd_line_script.test_non_ascii() on UNIX.

#13301: use ast.literal_eval() instead of eval() in Tools/i18n/msgfmt.py.  Patch by Serhiy Storchaka.

Thanks to Yongzhi Pan.

Thanks to Yongzhi Pan.

Thanks to Yongzhi Pan.

Thanks to Yongzhi Pan from docs@

Thanks to Yongzhi Pan from docs@

Thanks to Yongzhi Pan from docs@

from a Decimal argument.

Patch by Victor Stinner.

Patch by Victor Stinner.

Patch by Victor Stinner.