Fix bug #13079 on MS-Windows with temp files not being deleted.
src/w32.h (_child_process): New members input_file and
pending_deletion.
(register_child): First argument is now pid_t.
(record_infile, record_pending_deletion): New prototypes.
src/w32proc.c (new_child): Initialize input_file and
pending_deletion members of the child.
(delete_child): Delete the child's temporary input file, if any,
that is pending deletion.
(register_child): First argument is now pid_t.
(record_infile, record_pending_deletion): New functions.
(reap_subprocess): Fix a typo in DebPrint string.
(sys_spawnve, sys_kill): Use pid_t for PID arguments.
src/fileio.c (internal_delete_file): Return an int again: non-zero
if delete-file succeeds, zero otherwise.
src/lisp.h (internal_delete_file): Adjust prototype.
src/callproc.c (Fcall_process): Don't overwrite infile with result
of DECODE_FILE.
[WINDOWSNT] If BUFFER is an integer, i.e. we are launching an
asynchronous subprocess, record the name of the input file name,
if any.
(delete_temp_file) [WINDOWSNT]: If internal_delete_file fails to
delete the file, record it as pending deletion when the subprocess
exits.
nt/inc/ms-w32.h (sys_unlink): Provide prototype.