Implement spawn2ve() and spawn2vpe()

This has the following features over spawn2():

1. Split into spawn2ve() which is non-PATH-searching version and
   spawn2vpe() which is PATH-searching version.

2. Pass open file handles without FD_CLOEXEC to a child unless
   P_2_NOINEHRIT is given explicitly.

    modified:   Makefile
    modified:   check.cmd
    new file:   include/os2compat/spawn2.h
    new file:   process/spawn2.c
    new file:   process/spawn2.h
    modified:   testcase/Makefile
    new file:   testcase/spawn2-1.c
    new file:   testcase/spawn2-2.c

Makefile

@@ -177,6 +177,7 @@ HEADER_FILES := include/os2compat/dirent.h \
                 include/os2compat/poll.h \
                 include/os2compat/semaphore.h \
                 include/os2compat/sched.h \
+                include/os2compat/spawn2.h \
                 include/os2compat/net/if.h \
                 include/os2compat/sys/mman.h \
                 include/os2compat/sys/socket.h \
@@ -192,6 +193,7 @@ PRIV_HEADER_FILES := io/scandir.h \
                      network/shutdown.h \
                      network/socklen_t.h \
                      network/xpoll.h \
+                     process/spawn2.h \
                      thread/semaphore.h \
                      thread/sched_yield.h
 

check.cmd

@@ -65,6 +65,9 @@ call checkCC 'network/getifaddrs.h', 'network/getifaddrs.c', ,
              'struct ifaddrs *ifa;' || g.sNl ||,
              'getifaddrs( &ifa );' || g.sNl ||,
              'freeifaddrs( ifa );';
+call checkCC 'process/spawn2.h', 'process/spawn2.c', ,
+             'spawn2ve( 0, 0, 0, 0, 0, 0 );' || g.sNl ||,
+             'spawn2vpe( 0, 0, 0, 0, 0, 0 );';
 
 call checkOS2CompatHeader;
 
@@ -133,6 +136,7 @@ checkOS2CompatHeader: procedure expose G.
                    'include/os2compat/poll.h',
                    'include/os2compat/semaphore.h',
                    'include/os2compat/sched.h',
+                   'include/os2compat/spawn2.h',
                    'include/os2compat/net/if.h',
                    'include/os2compat/sys/mman.h',
                    'include/os2compat/sys/socket.h',
@@ -147,6 +151,7 @@ checkOS2CompatHeader: procedure expose G.
                        'network/shutdown.h',
                        'network/socklen_t.h',
                        'network/xpoll.h',
+                       'process/spawn2.h',
                        'thread/semaphore.h',
                        'thread/sched_yield.h';
     sDestDir = 'include/os2compat/priv';

include/os2compat/spawn2.h

@@ -0,0 +1,18 @@
+/*
+ * spawn2.h for os2compat
+ *
+ * Copyright (C) 2024 KO Myung-Hun <[email protected]>
+ *
+ * This program is free software. It comes without any warranty, to
+ * the extent permitted by applicable law. You can redistribute it
+ * and/or modify it under the terms of the Do What The Fuck You Want
+ * To Public License, Version 2, as published by Sam Hocevar. See
+ * http://www.wtfpl.net/ for more details.
+ */
+
+#ifndef OS2COMPAT_INCLUDE_SPAWN2_H
+#define OS2COMPAT_INCLUDE_SPAWN2_H
+
+#include "priv/process/spawn2.h"
+
+#endif