Use a pristine copy of argv to restart Emacs

Use a pristine copy of argv to restart Emacs

argv as left after main has proccessed the command-line can differ
both in order and contents of the original command-line arguments,
which can lead to surprising results when restarting emacs on the
cooked argv through `kill-emacs'.

Starting from that observation, consistenly use variables
'initial_cmdline' on Windows, 'initial_argc', 'initial_argv' on
non-Windows, and 'initial_argv0' in all ports.

* src/lisp.h: Declare 'initial_argv0', limit declaration of
'initial_argv' and 'initial_argc' to non-Windows ports.
* src/emacs.c: Likewise, but for the definitions.
(init_cmdargs): Move initialization of 'initial_argv' and
'initial_argc' ...
(copy_args) [!WINDOWSNT]: ... to this new function ...
(main): ... and call that in 'main', also initializing
'initial_argv0' before the command-line processing.
* src/emacs.c (Fkill_emacs):
* src/pgtkterm.c (pgtk_term_init):
* src/sysdep.c (emacs_perror):
* src/xterm.c (x_term_init): Use 'initial_argv0' where only that
is required.  (Bug#77389)

(cherry picked from commit e82989757f42e95bf72a2a55de415a8162a55dc3)