regenerate libcore/char_private.rs
(filed separately from the work in #45569, because of this matter of the updated Unicode data; see also #45567)
char_private.rs is generated programmatically by char_private.py, using data retrieved from the Unicode Consortium's website.
The motivation here was to make `is_printable` crate-visible (with `pub(crate)`), but it would seem that the Unicode data has changed slightly since char_private.rs was last generated.