emacsclient: don’t leak socket to child processes

* lib-src/emacsclient.c [!WINDOWSNT]: Include fcntl.h.
(cloexec_socket): New function.
(set_tcp_socket, set_local_socket): Use it.
1 job for master in 20 minutes and 54 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
failed #196
test

00:20:54

 
Name Stage Failure
failed
test Test
make[2]: *** [check-doit] Error 1
Makefile:301: recipe for target 'check-doit' failed
make[2]: Leaving directory '/builds/tzz/emacs/test'
make[1]: *** [check] Error 2
Makefile:271: recipe for target 'check' failed
make[1]: Leaving directory '/builds/tzz/emacs/test'
make: *** [check] Error 2
Makefile:955: recipe for target 'check' failed
ERROR: Job failed: exit code 1