Fixes issue #8052: The posix subprocess module's close_fds behavior was
suboptimal by closing all possible file descriptors rather than just
the open ones in the child process before exec().
It now closes only the open fds when it is possible to safely determine what
those are.
diff --git a/configure.in b/configure.in
index ef96da3..71e0a8f 100644
--- a/configure.in
+++ b/configure.in
@@ -1341,7 +1341,7 @@
sys/audioio.h sys/bsdtty.h sys/epoll.h sys/event.h sys/file.h sys/loadavg.h \
sys/lock.h sys/mkdev.h sys/modem.h \
sys/param.h sys/poll.h sys/select.h sys/socket.h sys/statvfs.h sys/stat.h \
-sys/termio.h sys/time.h \
+sys/syscall.h sys/termio.h sys/time.h \
sys/times.h sys/types.h sys/un.h sys/utsname.h sys/wait.h pty.h libutil.h \
sys/resource.h netpacket/packet.h sysexits.h bluetooth.h \
bluetooth/bluetooth.h linux/tipc.h spawn.h util.h)