since the standard require the caller pass the name explicitly
https://pubs.opengroup.org/onlinepubs/009695399/functions/posix_spawn.html:
The argument argv is an array of character pointers to null-terminated strings.
The last member of this array shall be a null pointer and is not counted in argc.
These strings constitute the argument list available to the new process image.
The value in argv[0] should point to a filename that is associated with the
process image being started by the posix_spawn() or posix_spawnp() function.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
bec68ad8ea