Integrate:

Integrate:
[ 22252]
Don't show code closing STD{IN,OUT} before reopening, because
doing so is unnecessary and occasionally harmful.

[ 22257]
threads documentation: fork on UNIX might not copy all threads.
p4raw-link: @22257 on //depot/perl: a95a5f75a0e72874474834cd9e274afa0f23b6d8
p4raw-link: @22252 on //depot/perl: 0c2f6559512b2211f892f1a6ae8db4739c5369b4

p4raw-id: //depot/maint-5.8/perl@22276
p4raw-integrated: from //depot/perl@22252 'merge in' pod/perlfunc.pod
	(@22248..)
p4raw-integrated: from //depot/perl@22251 'copy in' pod/perlfork.pod
	(@17137..) pod/perlthrtut.pod (@20492..)