- Add read1char_signals.patch to fix workers/36373

- Update to version 5.1
* The print builtin has new options -x and -X to expand tabs.
* Several new command completions and numerous updates to others.
* Options to "fc" to segregate internal and shared history.
* All emulations including "sh" use multibyte by default; several
repairs to multibyte handling.
* ZLE supports "bracketed paste" mode to avoid interpreting pasted
newlines as accept-line. Pastes can be highlighted for visibility
and to make it more obvious whether accept-line has occurred.
* Improved (though still not perfect) POSIX compatibility for getopts
builtin when POSIX_BUILTINS is set.
* New setopt APPEND_CREATE for POSIX-compatible NO_CLOBBER behavior.
* Completion of date values now displays in a calendar format when
the complist module is available. Controllable by zstyle.
* New parameter UNDO_LIMIT_NO for more control over ZLE undo repeat.
* Several repairs/improvements to the contributed narrow-to-region
ZLE function.
* Many changes to child-process and signal handling to eliminate race
conditions and avoid deadlocks on descriptor and memory management.
* New builtin sysopen in zsh/system module for detailed control of
file descriptor modes.
- Remove printf-regress.patch, upstream.