Integrate perlio:

[ 13934]
Fudge Config.pm so File::Spec does not croak.

[ 13931]
Define the two socket error numbers in terms of WSAEXXXXX equivalents
(just to get util.c to compile)

p4raw-link: @13934 on //depot/perlio: f7d174987f2e9e2d250eda5da71dd17f5435109e
p4raw-link: @13931 on //depot/perlio: 4fb841ef8b04e5aa481a43c3c82397c8c4f1ccfa

p4raw-id: //depot/perl@13935