Integrate from perlio:
Jarkko Hietaniemi [Sat, 18 Jan 2003 18:36:00 +0000 (18:36 +0000)]
[ 18507]
Thread-protection for dup/fclose/dup2 scheme of stdio leak
avoidance.
p4raw-link: @18507 on //depot/perlio: 997ec9b4c5029a8aa56f484e7b625da92e3e0521

p4raw-id: //depot/perl@18514


Trivial merge