* src/sysdep.c (struct speed_struct): New struct.
(speeds): New static array of struct speed_struct.
(convert_speed): New static function to convert a numerical baud
rate (e.g., 9600) to a Bnnn constant defined in termios.h (e.g.,
B9600).
(serial_configure): Use convert_speed to make the call to cfsetspeed
compliant with its advertised API.  (Bug#49524)

* src/callproc.c (get_current_directory): Rename from
'encode_current_directory' and add boolean ENCODE flag.
(Fcall_process): Interpret INFILE relative to the working directory
from which PROGRAM is run, not 'default-directory'.
(call_process): Use 'get_current_directory'.
* src/process.c (Fmake_process): Use 'get_current_directory'.
* src/process.h (get_current_directory): Rename decl from
'encode_current_directory'.
* src/sysdep.c (sys_subshell): Use 'get_current_directory' (bug#49283).

* src/sysdep.c (system_process_attributes): Fix misprint in 'tty' attr
- should be 'ttname' instead.  Change 'utime', 'stime', 'time',
'majflt' attrs to obtain them from proc_pid_rusage, as sysctl call
used before doesn't give correct values; remove 'minflt' because it's
not available.  Obtain 'vsize' / 'rss' / 'thcount' from proc_pidinfo.
Use sysctl with KERN_PROCARGS2 to obtain args: value contains both
argc and argv, so argv can be reliably cut out.

Problem reported by Ioannis Kappas (Bug#46388).
* src/sysdep.c (errputc) [WINDOWSNT]: Flush stderr after newline.

* src/sysdep.c (sigsegv_stack): Increase size to 64 KiB and align
it to max_align_t.  This copies from Gnulib’s c-stack.c, and works
around a portability bug in draft glibc 2.34, which no longer
defines SIGSTKSZ when _GNU_SOURCE is defined.

In some situations, e.g. when the Lisp machinery isn't available, we
can't quit.  Don't check the quit flags in such situations, in case
they contain garbage.

* src/sysdep.c (emacs_open_noquit, emacs_openat_noquit): New variants
of 'emacs_open' and 'emacs_openat' that don't check the quit flags.

* src/emacs.c (main, Fdaemon_initialized):
* src/pdumper.c (pdumper_load):
* src/w32term.c (w32_initialize):
* src/buffer.c (mmap_init):
* src/callproc.c (emacs_spawn): Use them where we can't quit.

* src/sysdep.c (make_lisp_timeval):
(system_process_attributes): Implement for OpenBSD (bug#45729).

Run "TZ=UTC0 admin/update-copyright".

The latest Gnulib merge brought in free-posix, which causes 'free'
to preserve errno.  This lets us simplify some Emacs code that
calls 'free'.
* admin/merge-gnulib (GNULIB_MODULES): Add free-posix.
This module is pulled in by canonicalize-lgpl anyway,
so we might as well rely on it.
* lib-src/emacsclient.c (get_current_dir_name):
Sync better with src/sysdep.c.
* lib-src/etags.c (process_file_name, etags_mktmp):
* lib-src/update-game-score.c (unlock_file):
* src/fileio.c (file_accessible_directory_p):
* src/sysdep.c (get_current_dir_name_or_unreachable):
Simplify by assuming that 'free' preserves errno.
* src/alloc.c (malloc_unblock_input):
Preserve errno, so that xfree preserves errno.
* src/sysdep.c (get_current_dir_name_or_unreachable):
Simplify by using strdup instead of malloc+memcpy.
No need for realloc (and the old code leaked memory anyway on
failure); just use free+malloc.